Many laser operations, especially in research applications, involve Class 3B and Class 4 beams of multiple wavelengths. Protective eyewear for the accessible laser beams can then pose a significant challenge, especially if these wavelengths span a significant portion of the 400-700 nm visible spectrum. The Laser Safety Officer must perform a good hazard evaluation to determine the best combination of engineering, administrative and PPE (personal protective equipment) controls to ensure there is an acceptable level of risk for the laser workers. This evaluation has to employ a hazard controls hierarchy, which gives highest priority to engineering controls.Examples of multi-wavelength operations include: multiple laser sources; tunable OPAs, OPOs, and OPCPAs; and “white light” continuum lasers. Engineering, administrative and PPE controls for some examples of these are discussed. Full protection laser eyewear should be used for accessible laser beams, but considerations for alignment eyewear and remote operation are also needed.Many laser operations, especially in research applications, involve Class 3B and Class 4 beams of multiple wavelengths. Protective eyewear for the accessible laser beams can then pose a significant challenge, especially if these wavelengths span a significant portion of the 400-700 nm visible spectrum. The Laser Safety Officer must perform a good hazard evaluation to determine the best combination of engineering, administrative and PPE (personal protective equipment) controls to ensure there is an acceptable level of risk for the laser workers. This evaluation has to employ a hazard controls hierarchy, which gives highest priority to engineering controls.Examples of multi-wavelength operations include: multiple laser sources; tunable OPAs, OPOs, and OPCPAs; and “white light” continuum lasers. Engineering, administrative and PPE controls for some examples of these are discussed. Full protection laser eyewear should be used for accessible laser beams, but considerations for alignment eyewear and remote oper...
{"title":"Controls for multi-wavelength, tunable and continuum lasers","authors":"M. Woods","doi":"10.2351/1.5118663","DOIUrl":"https://doi.org/10.2351/1.5118663","url":null,"abstract":"Many laser operations, especially in research applications, involve Class 3B and Class 4 beams of multiple wavelengths. Protective eyewear for the accessible laser beams can then pose a significant challenge, especially if these wavelengths span a significant portion of the 400-700 nm visible spectrum. The Laser Safety Officer must perform a good hazard evaluation to determine the best combination of engineering, administrative and PPE (personal protective equipment) controls to ensure there is an acceptable level of risk for the laser workers. This evaluation has to employ a hazard controls hierarchy, which gives highest priority to engineering controls.Examples of multi-wavelength operations include: multiple laser sources; tunable OPAs, OPOs, and OPCPAs; and “white light” continuum lasers. Engineering, administrative and PPE controls for some examples of these are discussed. Full protection laser eyewear should be used for accessible laser beams, but considerations for alignment eyewear and remote operation are also needed.Many laser operations, especially in research applications, involve Class 3B and Class 4 beams of multiple wavelengths. Protective eyewear for the accessible laser beams can then pose a significant challenge, especially if these wavelengths span a significant portion of the 400-700 nm visible spectrum. The Laser Safety Officer must perform a good hazard evaluation to determine the best combination of engineering, administrative and PPE (personal protective equipment) controls to ensure there is an acceptable level of risk for the laser workers. This evaluation has to employ a hazard controls hierarchy, which gives highest priority to engineering controls.Examples of multi-wavelength operations include: multiple laser sources; tunable OPAs, OPOs, and OPCPAs; and “white light” continuum lasers. Engineering, administrative and PPE controls for some examples of these are discussed. Full protection laser eyewear should be used for accessible laser beams, but considerations for alignment eyewear and remote oper...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"210 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123849908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper attempts to address the issues raised when the Specialist Radiation Inspectorate for the Health and Safety Executive - the UK Government Executive Inspectorate for Health and Safety comes to call.The specific questions this paper attempts to address: Where did we come from as an organisation in terms of laser safety compliance? How our organisation structured and was this appropriate? What local issues did we have? What lessons did we take away from the experience? This paper examines the practical issues posed when one of the UKs largest technical Universities with possibly the most diverse range of laser research laboratories has moved towards full UK laser safety regulatory compliance.This paper attempts to address the issues raised when the Specialist Radiation Inspectorate for the Health and Safety Executive - the UK Government Executive Inspectorate for Health and Safety comes to call.The specific questions this paper attempts to address: Where did we come from as an organisation in terms of laser safety compliance? How our organisation structured and was this appropriate? What local issues did we have? What lessons did we take away from the experience? This paper examines the practical issues posed when one of the UKs largest technical Universities with possibly the most diverse range of laser research laboratories has moved towards full UK laser safety regulatory compliance.
{"title":"Being on the receiving end of a government laser safety inspectors formal laboratories inspection","authors":"J. Tyrer","doi":"10.2351/1.5118533","DOIUrl":"https://doi.org/10.2351/1.5118533","url":null,"abstract":"This paper attempts to address the issues raised when the Specialist Radiation Inspectorate for the Health and Safety Executive - the UK Government Executive Inspectorate for Health and Safety comes to call.The specific questions this paper attempts to address: Where did we come from as an organisation in terms of laser safety compliance? How our organisation structured and was this appropriate? What local issues did we have? What lessons did we take away from the experience? This paper examines the practical issues posed when one of the UKs largest technical Universities with possibly the most diverse range of laser research laboratories has moved towards full UK laser safety regulatory compliance.This paper attempts to address the issues raised when the Specialist Radiation Inspectorate for the Health and Safety Executive - the UK Government Executive Inspectorate for Health and Safety comes to call.The specific questions this paper attempts to address: Where did we come from as an organisation in terms of laser safety compliance? How our organisation structured and was this appropriate? What local issues did we have? What lessons did we take away from the experience? This paper examines the practical issues posed when one of the UKs largest technical Universities with possibly the most diverse range of laser research laboratories has moved towards full UK laser safety regulatory compliance.","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130182545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction/Objectives Significant bacterial contamination of dental implant surfaces is associated with supporting bone degeneration, and traditional mechanical debridement treatments are often met with low rates of regenerative success. It has been demonstrated in previous studies that diode laser irradiation is capable of decontaminating titanium alloys that commonly comprise dental implants. Although diode laser irradiation can efficiently rid these surfaces of bacteria, prolonged use of laser systems on dental implants has the potential for dangerous thermal stresses on metallic surfaces and surrounding osseous tissues. The aim of this study was to assess implant surface thermometry after diode laser irradiation, and to develop optimal thermal safety recommendations for dental clinicians. Methods An in-vitro model comparative to a clinical presentation of peri-implantitis was created via placement of a 3.5x11mm titanium alloy dental implant into artificial Type-II bovine bone, and an irregular 3x5mm osseous segment was removed to create an infrabony defect. Diode laser systems of varying wavelengths (810nm, 940nm, 975nm, and 980nm) were subjected to different initiator pigments (uninitiated, blue, and cork) and beam types (continuous wave or pulsed mode) prior to surface irradiation. Axial implant surfaces were debrided at 2W mean power for 15 trials/group that were 30-seconds in duration. Implant surface temperature was monitored via apical and coronal thermocouple devices over these irradiation periods. Results The critical biologic thermal safety threshold for osseous necrosis (Δ+10°C) was commonly surpassed in continuous wave trials regardless of initiator or power condition. Initiated fibers achieved significantly faster changes in temperature than non-initiated fibers. Coronal implant surfaces demonstrated significantly greater temperature increases than that of apical portions, with no apical readings surpassing the critical biologic thermal safety threshold. Different initiating pigments were preferred to best control thermal climb for different wavelength diode systems. Conclusion Within study limitations, mean power settings for implant surface debridement should be less than manufacture recommendations to minimize risks of overheating and consequential implant failure. Utilization of pulsed modes and wavelength-specific initiators are necessary for thermal protection of implant titanium alloy surfaces and supporting bony structures during clinical decontamination. Introduction/Objectives Significant bacterial contamination of dental implant surfaces is associated with supporting bone degeneration, and traditional mechanical debridement treatments are often met with low rates of regenerative success. It has been demonstrated in previous studies that diode laser irradiation is capable of decontaminating titanium alloys that commonly comprise dental implants. Although diode laser irradiation can efficiently rid these surfaces of bac
{"title":"Optimization of thermal protocols during diode irradiation of dental implants","authors":"Nicholas J. Montanaro, Gaby Bekov, G. Romanos","doi":"10.2351/1.5118639","DOIUrl":"https://doi.org/10.2351/1.5118639","url":null,"abstract":"Introduction/Objectives Significant bacterial contamination of dental implant surfaces is associated with supporting bone degeneration, and traditional mechanical debridement treatments are often met with low rates of regenerative success. It has been demonstrated in previous studies that diode laser irradiation is capable of decontaminating titanium alloys that commonly comprise dental implants. Although diode laser irradiation can efficiently rid these surfaces of bacteria, prolonged use of laser systems on dental implants has the potential for dangerous thermal stresses on metallic surfaces and surrounding osseous tissues. The aim of this study was to assess implant surface thermometry after diode laser irradiation, and to develop optimal thermal safety recommendations for dental clinicians. Methods An in-vitro model comparative to a clinical presentation of peri-implantitis was created via placement of a 3.5x11mm titanium alloy dental implant into artificial Type-II bovine bone, and an irregular 3x5mm osseous segment was removed to create an infrabony defect. Diode laser systems of varying wavelengths (810nm, 940nm, 975nm, and 980nm) were subjected to different initiator pigments (uninitiated, blue, and cork) and beam types (continuous wave or pulsed mode) prior to surface irradiation. Axial implant surfaces were debrided at 2W mean power for 15 trials/group that were 30-seconds in duration. Implant surface temperature was monitored via apical and coronal thermocouple devices over these irradiation periods. Results The critical biologic thermal safety threshold for osseous necrosis (Δ+10°C) was commonly surpassed in continuous wave trials regardless of initiator or power condition. Initiated fibers achieved significantly faster changes in temperature than non-initiated fibers. Coronal implant surfaces demonstrated significantly greater temperature increases than that of apical portions, with no apical readings surpassing the critical biologic thermal safety threshold. Different initiating pigments were preferred to best control thermal climb for different wavelength diode systems. Conclusion Within study limitations, mean power settings for implant surface debridement should be less than manufacture recommendations to minimize risks of overheating and consequential implant failure. Utilization of pulsed modes and wavelength-specific initiators are necessary for thermal protection of implant titanium alloy surfaces and supporting bony structures during clinical decontamination. Introduction/Objectives Significant bacterial contamination of dental implant surfaces is associated with supporting bone degeneration, and traditional mechanical debridement treatments are often met with low rates of regenerative success. It has been demonstrated in previous studies that diode laser irradiation is capable of decontaminating titanium alloys that commonly comprise dental implants. Although diode laser irradiation can efficiently rid these surfaces of bac","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115653525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adam R. Boretsky, Joseph E. Clary, G. Noojin, Dixie J. Burner, B. Rockwell
Ultrafast lasers are capable of generating extremely high peak powers and inducing non-linear optical phenomena that may be hazardous to sensitive ocular tissue. The generation of broadband supercontinuum light from ultrafast near infrared (NIR) lasers is of particular interest because of the potential damaging effects on both the cornea and retina. Freshly excised porcine eyes and an artificial model eye proved to be suitable systems to investigate non-linear optical phenomena due to the similarity in size and optical properties to the human eye. A tunable optical parametric amplifier (OPA) with a nominal pulse with of 100 femtoseconds generated all laser exposures in the 1200-1500 nm range. A fiber-based spectrometer introduced into the back of excised porcine eyes through a small incision in the sclera and placed at the retinal plane measured spectral broadening of the NIR femtosecond laser pulses. Changes in the spectral profile of the supercontinuum light were observed at multiple pulse energies and monitored dynamically as the position of the beam focus was adjusted with respect to the corneal surface. Further consideration of non-linear optical hazards may be required to ensure the safe use of ultrafast lasers as they become more prevalent in life sciences, telecommunications, industrial processing, and biomedical applications.Ultrafast lasers are capable of generating extremely high peak powers and inducing non-linear optical phenomena that may be hazardous to sensitive ocular tissue. The generation of broadband supercontinuum light from ultrafast near infrared (NIR) lasers is of particular interest because of the potential damaging effects on both the cornea and retina. Freshly excised porcine eyes and an artificial model eye proved to be suitable systems to investigate non-linear optical phenomena due to the similarity in size and optical properties to the human eye. A tunable optical parametric amplifier (OPA) with a nominal pulse with of 100 femtoseconds generated all laser exposures in the 1200-1500 nm range. A fiber-based spectrometer introduced into the back of excised porcine eyes through a small incision in the sclera and placed at the retinal plane measured spectral broadening of the NIR femtosecond laser pulses. Changes in the spectral profile of the supercontinuum light were observed at multiple pulse energies and ...
{"title":"Non-linear optical hazards from near-infrared ultrafast laser pulses in ocular tissue","authors":"Adam R. Boretsky, Joseph E. Clary, G. Noojin, Dixie J. Burner, B. Rockwell","doi":"10.2351/1.5118571","DOIUrl":"https://doi.org/10.2351/1.5118571","url":null,"abstract":"Ultrafast lasers are capable of generating extremely high peak powers and inducing non-linear optical phenomena that may be hazardous to sensitive ocular tissue. The generation of broadband supercontinuum light from ultrafast near infrared (NIR) lasers is of particular interest because of the potential damaging effects on both the cornea and retina. Freshly excised porcine eyes and an artificial model eye proved to be suitable systems to investigate non-linear optical phenomena due to the similarity in size and optical properties to the human eye. A tunable optical parametric amplifier (OPA) with a nominal pulse with of 100 femtoseconds generated all laser exposures in the 1200-1500 nm range. A fiber-based spectrometer introduced into the back of excised porcine eyes through a small incision in the sclera and placed at the retinal plane measured spectral broadening of the NIR femtosecond laser pulses. Changes in the spectral profile of the supercontinuum light were observed at multiple pulse energies and monitored dynamically as the position of the beam focus was adjusted with respect to the corneal surface. Further consideration of non-linear optical hazards may be required to ensure the safe use of ultrafast lasers as they become more prevalent in life sciences, telecommunications, industrial processing, and biomedical applications.Ultrafast lasers are capable of generating extremely high peak powers and inducing non-linear optical phenomena that may be hazardous to sensitive ocular tissue. The generation of broadband supercontinuum light from ultrafast near infrared (NIR) lasers is of particular interest because of the potential damaging effects on both the cornea and retina. Freshly excised porcine eyes and an artificial model eye proved to be suitable systems to investigate non-linear optical phenomena due to the similarity in size and optical properties to the human eye. A tunable optical parametric amplifier (OPA) with a nominal pulse with of 100 femtoseconds generated all laser exposures in the 1200-1500 nm range. A fiber-based spectrometer introduced into the back of excised porcine eyes through a small incision in the sclera and placed at the retinal plane measured spectral broadening of the NIR femtosecond laser pulses. Changes in the spectral profile of the supercontinuum light were observed at multiple pulse energies and ...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128168783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Knowledge is the best defense. Wearing the wrong laser goggles is more dangerous than not wearing goggles at all. Misunderstanding how a polarizer or a beam splitter works has resulted in a large number of laser accidents. People learn the most when they do things. A practical session of laser safety training is considered essential. Building a laser lab for the practical session of the training can be too demanding for the budget of an Office of Health and Safety. On the other hand, the LSOs in large universities are involved in the decommissioning of many lasers and instruments containing lasers. Although such equipment is old and generally considered obsolete for research purposes they contain valuable lasers and optical components ideal for a laser-teaching lab. In this paper, the authors will present examples of recycled lasers and laser components currently used as props in the classroom during oral presentations and in the practical laser-teaching lab at our university.Knowledge is the best defense. Wearing the wrong laser goggles is more dangerous than not wearing goggles at all. Misunderstanding how a polarizer or a beam splitter works has resulted in a large number of laser accidents. People learn the most when they do things. A practical session of laser safety training is considered essential. Building a laser lab for the practical session of the training can be too demanding for the budget of an Office of Health and Safety. On the other hand, the LSOs in large universities are involved in the decommissioning of many lasers and instruments containing lasers. Although such equipment is old and generally considered obsolete for research purposes they contain valuable lasers and optical components ideal for a laser-teaching lab. In this paper, the authors will present examples of recycled lasers and laser components currently used as props in the classroom during oral presentations and in the practical laser-teaching lab at our university.
{"title":"Laser decommissioning and practical laser training","authors":"S. Sonoc, G. Moriena","doi":"10.2351/1.5118534","DOIUrl":"https://doi.org/10.2351/1.5118534","url":null,"abstract":"Knowledge is the best defense. Wearing the wrong laser goggles is more dangerous than not wearing goggles at all. Misunderstanding how a polarizer or a beam splitter works has resulted in a large number of laser accidents. People learn the most when they do things. A practical session of laser safety training is considered essential. Building a laser lab for the practical session of the training can be too demanding for the budget of an Office of Health and Safety. On the other hand, the LSOs in large universities are involved in the decommissioning of many lasers and instruments containing lasers. Although such equipment is old and generally considered obsolete for research purposes they contain valuable lasers and optical components ideal for a laser-teaching lab. In this paper, the authors will present examples of recycled lasers and laser components currently used as props in the classroom during oral presentations and in the practical laser-teaching lab at our university.Knowledge is the best defense. Wearing the wrong laser goggles is more dangerous than not wearing goggles at all. Misunderstanding how a polarizer or a beam splitter works has resulted in a large number of laser accidents. People learn the most when they do things. A practical session of laser safety training is considered essential. Building a laser lab for the practical session of the training can be too demanding for the budget of an Office of Health and Safety. On the other hand, the LSOs in large universities are involved in the decommissioning of many lasers and instruments containing lasers. Although such equipment is old and generally considered obsolete for research purposes they contain valuable lasers and optical components ideal for a laser-teaching lab. In this paper, the authors will present examples of recycled lasers and laser components currently used as props in the classroom during oral presentations and in the practical laser-teaching lab at our university.","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116959839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The advent of so-called “fifth-generation” low-observable strike aircraft with a laser designation capability raises a potentially unique laser hazard. In order to be “stealthy”, the laser designator is likely to be embedded within the aircraft rather than carried externally as a podded system. The difference between an integrated and a pod-based configuration is that the laser exit window in a stealth design is likely to be fixed to the aircraft fuselage, as opposed to being able to move with the laser beam, and it is also likely to be faceted. Unless carefully engineered, a faceted exit window may generate unintended laser beam reflections resulting in stray laser energy (SLE) emissions, as the laser head rotates within the window assembly.High intensity SLE can engender impractically large laser hazard zones using traditional deterministic analysis techniques. The purpose of this paper is to outline the probabilistic modelling of uncontrolled SLE from a hypothetical integrated laser designator system. The discussion will also show the importance of including the aircraft behaviour in the analysis, due to the effect of the aircraft position relative to the target on the SLE scatter patterns.The advent of so-called “fifth-generation” low-observable strike aircraft with a laser designation capability raises a potentially unique laser hazard. In order to be “stealthy”, the laser designator is likely to be embedded within the aircraft rather than carried externally as a podded system. The difference between an integrated and a pod-based configuration is that the laser exit window in a stealth design is likely to be fixed to the aircraft fuselage, as opposed to being able to move with the laser beam, and it is also likely to be faceted. Unless carefully engineered, a faceted exit window may generate unintended laser beam reflections resulting in stray laser energy (SLE) emissions, as the laser head rotates within the window assembly.High intensity SLE can engender impractically large laser hazard zones using traditional deterministic analysis techniques. The purpose of this paper is to outline the probabilistic modelling of uncontrolled SLE from a hypothetical integrated laser designator system. ...
{"title":"Probabilistic laser hazard modelling for a fifth-generation low-observable laser designator system","authors":"B. Flemming","doi":"10.2351/1.5118528","DOIUrl":"https://doi.org/10.2351/1.5118528","url":null,"abstract":"The advent of so-called “fifth-generation” low-observable strike aircraft with a laser designation capability raises a potentially unique laser hazard. In order to be “stealthy”, the laser designator is likely to be embedded within the aircraft rather than carried externally as a podded system. The difference between an integrated and a pod-based configuration is that the laser exit window in a stealth design is likely to be fixed to the aircraft fuselage, as opposed to being able to move with the laser beam, and it is also likely to be faceted. Unless carefully engineered, a faceted exit window may generate unintended laser beam reflections resulting in stray laser energy (SLE) emissions, as the laser head rotates within the window assembly.High intensity SLE can engender impractically large laser hazard zones using traditional deterministic analysis techniques. The purpose of this paper is to outline the probabilistic modelling of uncontrolled SLE from a hypothetical integrated laser designator system. The discussion will also show the importance of including the aircraft behaviour in the analysis, due to the effect of the aircraft position relative to the target on the SLE scatter patterns.The advent of so-called “fifth-generation” low-observable strike aircraft with a laser designation capability raises a potentially unique laser hazard. In order to be “stealthy”, the laser designator is likely to be embedded within the aircraft rather than carried externally as a podded system. The difference between an integrated and a pod-based configuration is that the laser exit window in a stealth design is likely to be fixed to the aircraft fuselage, as opposed to being able to move with the laser beam, and it is also likely to be faceted. Unless carefully engineered, a faceted exit window may generate unintended laser beam reflections resulting in stray laser energy (SLE) emissions, as the laser head rotates within the window assembly.High intensity SLE can engender impractically large laser hazard zones using traditional deterministic analysis techniques. The purpose of this paper is to outline the probabilistic modelling of uncontrolled SLE from a hypothetical integrated laser designator system. ...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114492011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mathieu Jean, Sebastian Kotzur, N. Heussner, K. Schulmeister, A. Frederiksen
Neither the international laser safety standard IEC 60825-1 Edition 3.0 nor the standard ANSI Z136.1-2014 provide specific rules on how to apply the pulse reduction factor C5 (resp. CP) to irregular pulse trains, featuring both varying peak power as well as varying pulse duration. Without specific guidance, the analysis has to be performed based on restrictive approaches, such as counting all pulses and giving them the same weight, even the ones with smaller peak power and lower energy. Preliminary work, presented at the ILSC 2017, focused on pulse trains with varying peak power. The present study provides guidance on how to analyze irregular pulse patterns - both in terms of peak power and pulse duration - in a less restrictive way.Neither the international laser safety standard IEC 60825-1 Edition 3.0 nor the standard ANSI Z136.1-2014 provide specific rules on how to apply the pulse reduction factor C5 (resp. CP) to irregular pulse trains, featuring both varying peak power as well as varying pulse duration. Without specific guidance, the analysis has to be performed based on restrictive approaches, such as counting all pulses and giving them the same weight, even the ones with smaller peak power and lower energy. Preliminary work, presented at the ILSC 2017, focused on pulse trains with varying peak power. The present study provides guidance on how to analyze irregular pulse patterns - both in terms of peak power and pulse duration - in a less restrictive way.
{"title":"Computer modelling to support laser safety analysis of pulse trains with varying peak power and pulse duration","authors":"Mathieu Jean, Sebastian Kotzur, N. Heussner, K. Schulmeister, A. Frederiksen","doi":"10.2351/1.5118564","DOIUrl":"https://doi.org/10.2351/1.5118564","url":null,"abstract":"Neither the international laser safety standard IEC 60825-1 Edition 3.0 nor the standard ANSI Z136.1-2014 provide specific rules on how to apply the pulse reduction factor C5 (resp. CP) to irregular pulse trains, featuring both varying peak power as well as varying pulse duration. Without specific guidance, the analysis has to be performed based on restrictive approaches, such as counting all pulses and giving them the same weight, even the ones with smaller peak power and lower energy. Preliminary work, presented at the ILSC 2017, focused on pulse trains with varying peak power. The present study provides guidance on how to analyze irregular pulse patterns - both in terms of peak power and pulse duration - in a less restrictive way.Neither the international laser safety standard IEC 60825-1 Edition 3.0 nor the standard ANSI Z136.1-2014 provide specific rules on how to apply the pulse reduction factor C5 (resp. CP) to irregular pulse trains, featuring both varying peak power as well as varying pulse duration. Without specific guidance, the analysis has to be performed based on restrictive approaches, such as counting all pulses and giving them the same weight, even the ones with smaller peak power and lower energy. Preliminary work, presented at the ILSC 2017, focused on pulse trains with varying peak power. The present study provides guidance on how to analyze irregular pulse patterns - both in terms of peak power and pulse duration - in a less restrictive way.","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125294638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the wavelength range of 400 nm to 1400 nm, the retinal thermal exposure or emission limits depend on the angular subtense of the apparent source (Greek symbol “alpha”). For the case that a given laser beam is associated to an extended source, according to IEC 60825-1 or ANSI Z136.1 the emission permitted for a given class (such as Class 1) can be substantially higher as compared to the case of a small source. In this paper, earlier discussions on the classification concept to analyse extended sources are summarized and commented. While it is historically justified to refer to the “apparent source” such as when the optical source is a diffusor as the classical example of an extended source, the more general understanding and terminology is to associate “alpha” with the angular subtense of the retinal image, i.e. the irradiance profile on the retina. This is particularly important when the aperture stop on the imaging system (the eye) reduces significantly the retinal image as compared to the angular subtense of the source, which is possible for coherent and partially coherent beams. In a second part of the paper, modelling results for the potential impact of the aperture stop to reduce the retinal image are discussed for the example of two partially coherent beams.In the wavelength range of 400 nm to 1400 nm, the retinal thermal exposure or emission limits depend on the angular subtense of the apparent source (Greek symbol “alpha”). For the case that a given laser beam is associated to an extended source, according to IEC 60825-1 or ANSI Z136.1 the emission permitted for a given class (such as Class 1) can be substantially higher as compared to the case of a small source. In this paper, earlier discussions on the classification concept to analyse extended sources are summarized and commented. While it is historically justified to refer to the “apparent source” such as when the optical source is a diffusor as the classical example of an extended source, the more general understanding and terminology is to associate “alpha” with the angular subtense of the retinal image, i.e. the irradiance profile on the retina. This is particularly important when the aperture stop on the imaging system (the eye) reduces significantly the retinal image as compared to the angular sub...
{"title":"Notes on the determination of the angular subtense of the apparent source in laser safety","authors":"K. Schulmeister","doi":"10.2351/1.5118538","DOIUrl":"https://doi.org/10.2351/1.5118538","url":null,"abstract":"In the wavelength range of 400 nm to 1400 nm, the retinal thermal exposure or emission limits depend on the angular subtense of the apparent source (Greek symbol “alpha”). For the case that a given laser beam is associated to an extended source, according to IEC 60825-1 or ANSI Z136.1 the emission permitted for a given class (such as Class 1) can be substantially higher as compared to the case of a small source. In this paper, earlier discussions on the classification concept to analyse extended sources are summarized and commented. While it is historically justified to refer to the “apparent source” such as when the optical source is a diffusor as the classical example of an extended source, the more general understanding and terminology is to associate “alpha” with the angular subtense of the retinal image, i.e. the irradiance profile on the retina. This is particularly important when the aperture stop on the imaging system (the eye) reduces significantly the retinal image as compared to the angular subtense of the source, which is possible for coherent and partially coherent beams. In a second part of the paper, modelling results for the potential impact of the aperture stop to reduce the retinal image are discussed for the example of two partially coherent beams.In the wavelength range of 400 nm to 1400 nm, the retinal thermal exposure or emission limits depend on the angular subtense of the apparent source (Greek symbol “alpha”). For the case that a given laser beam is associated to an extended source, according to IEC 60825-1 or ANSI Z136.1 the emission permitted for a given class (such as Class 1) can be substantially higher as compared to the case of a small source. In this paper, earlier discussions on the classification concept to analyse extended sources are summarized and commented. While it is historically justified to refer to the “apparent source” such as when the optical source is a diffusor as the classical example of an extended source, the more general understanding and terminology is to associate “alpha” with the angular subtense of the retinal image, i.e. the irradiance profile on the retina. This is particularly important when the aperture stop on the imaging system (the eye) reduces significantly the retinal image as compared to the angular sub...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120968187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laser applications traditionally do not consider chronic exposure from intended viewing. However, in recent years some applications of lasers in displays and laser facial recognition and 3-D spatial scanning suggest the need to re-visit the current exposure limits for exposure - and viewing - durations for periods of many minutes to hours.Laser applications traditionally do not consider chronic exposure from intended viewing. However, in recent years some applications of lasers in displays and laser facial recognition and 3-D spatial scanning suggest the need to re-visit the current exposure limits for exposure - and viewing - durations for periods of many minutes to hours.
{"title":"Revisiting laser exposure limits for intended viewing","authors":"D. Sliney","doi":"10.2351/1.5118531","DOIUrl":"https://doi.org/10.2351/1.5118531","url":null,"abstract":"Laser applications traditionally do not consider chronic exposure from intended viewing. However, in recent years some applications of lasers in displays and laser facial recognition and 3-D spatial scanning suggest the need to re-visit the current exposure limits for exposure - and viewing - durations for periods of many minutes to hours.Laser applications traditionally do not consider chronic exposure from intended viewing. However, in recent years some applications of lasers in displays and laser facial recognition and 3-D spatial scanning suggest the need to re-visit the current exposure limits for exposure - and viewing - durations for periods of many minutes to hours.","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132205840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The laser technology has been for a long time confined to professional uses but is more and more integrated into consumer products and complex systems. In this regard, the particular case of 3R products has re-opened controversial and unconcluded discussions among experts concerning the safety requirements. In parallel, the European standardization organization CENELEC is about to give its conclusion to the European Commission on acceptable laser products for consumers. The task is quite complex, especially with respect to the modifications introduced in the calculation of the Admissible Emission Limits (AEL) in the 3rd edition of the laser norm IEC 60825-1. The classification of laser systems, based on the worst-case assumption, is not well reflecting the risk of the user exposition. Because of the moving beam condition it is unlikely for scanning systems to meet all worst-case conditions of multiple and independent parameters at the same time. Apart from this, some particular parameters concerning extended sources and pulsed sources classified 3R under the 3rd edition of the IEC 60825-1 are seen critical as the AEL can in some cases exceed known injury threshold values. We define in this paper the concept of a Continuously Scanning Laser System (CSLS) and analyze under these conditions the behavior of the AEL for these critical parameters. We finally conclude that CSLS products classified 3R belong to the low risk 3R group.The laser technology has been for a long time confined to professional uses but is more and more integrated into consumer products and complex systems. In this regard, the particular case of 3R products has re-opened controversial and unconcluded discussions among experts concerning the safety requirements. In parallel, the European standardization organization CENELEC is about to give its conclusion to the European Commission on acceptable laser products for consumers. The task is quite complex, especially with respect to the modifications introduced in the calculation of the Admissible Emission Limits (AEL) in the 3rd edition of the laser norm IEC 60825-1. The classification of laser systems, based on the worst-case assumption, is not well reflecting the risk of the user exposition. Because of the moving beam condition it is unlikely for scanning systems to meet all worst-case conditions of multiple and independent parameters at the same time. Apart from this, some particular parameters concerning exten...
{"title":"Investigation on continuously scanning laser systems classified 3R under the IEC 60825-1 edition 3.0 in consumer products","authors":"Gael Pilard, Hendrik Specht","doi":"10.2351/1.5118580","DOIUrl":"https://doi.org/10.2351/1.5118580","url":null,"abstract":"The laser technology has been for a long time confined to professional uses but is more and more integrated into consumer products and complex systems. In this regard, the particular case of 3R products has re-opened controversial and unconcluded discussions among experts concerning the safety requirements. In parallel, the European standardization organization CENELEC is about to give its conclusion to the European Commission on acceptable laser products for consumers. The task is quite complex, especially with respect to the modifications introduced in the calculation of the Admissible Emission Limits (AEL) in the 3rd edition of the laser norm IEC 60825-1. The classification of laser systems, based on the worst-case assumption, is not well reflecting the risk of the user exposition. Because of the moving beam condition it is unlikely for scanning systems to meet all worst-case conditions of multiple and independent parameters at the same time. Apart from this, some particular parameters concerning extended sources and pulsed sources classified 3R under the 3rd edition of the IEC 60825-1 are seen critical as the AEL can in some cases exceed known injury threshold values. We define in this paper the concept of a Continuously Scanning Laser System (CSLS) and analyze under these conditions the behavior of the AEL for these critical parameters. We finally conclude that CSLS products classified 3R belong to the low risk 3R group.The laser technology has been for a long time confined to professional uses but is more and more integrated into consumer products and complex systems. In this regard, the particular case of 3R products has re-opened controversial and unconcluded discussions among experts concerning the safety requirements. In parallel, the European standardization organization CENELEC is about to give its conclusion to the European Commission on acceptable laser products for consumers. The task is quite complex, especially with respect to the modifications introduced in the calculation of the Admissible Emission Limits (AEL) in the 3rd edition of the laser norm IEC 60825-1. The classification of laser systems, based on the worst-case assumption, is not well reflecting the risk of the user exposition. Because of the moving beam condition it is unlikely for scanning systems to meet all worst-case conditions of multiple and independent parameters at the same time. Apart from this, some particular parameters concerning exten...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132037724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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