Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cma3
V. Krylov, O. Ollikainen, J. Gallus, U. Wild, V. Bespalov, D. Staselko, A. Rebane
Stimulated Raman scattering (SRS) in gases is an efficient method of frequency conversion of laser pulses with nano- pico and femtosecond [1] duration in the broad spectral range from UV to near IR. Previously we have shown that H2, D2, HD and CH4 are most appropriate media for transient femtosecond SRS due to large transient gain coefficient, short molecular relaxation time T2 and high optical breakdown threshold. Due to coherent character of Stokes- and anti-Stokes components, it has been suggested to use SRS for producing ultrashort pulses in sub-10-fs duration range [2].
{"title":"Broadband femtosecond stimulated Raman scattering in H2-D2, H2-HD and H2-CH4 gas mixtures","authors":"V. Krylov, O. Ollikainen, J. Gallus, U. Wild, V. Bespalov, D. Staselko, A. Rebane","doi":"10.1364/cleo_europe.1998.cma3","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cma3","url":null,"abstract":"Stimulated Raman scattering (SRS) in gases is an efficient method of frequency conversion of laser pulses with nano- pico and femtosecond [1] duration in the broad spectral range from UV to near IR. Previously we have shown that H2, D2, HD and CH4 are most appropriate media for transient femtosecond SRS due to large transient gain coefficient, short molecular relaxation time T2 and high optical breakdown threshold. Due to coherent character of Stokes- and anti-Stokes components, it has been suggested to use SRS for producing ultrashort pulses in sub-10-fs duration range [2].","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84238196","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cmi6
T. Eriksen, U. Hoppe, E. Thrane, T. Blix
Two new rocket-borne Rayleigh lidar experiments were developed at the Norwegian Defence Research Establishment and launched from Andøya Rocket Range in October 97 and January 98. The aim of the experiments were to measure the neutral atmosphere number density and to study the dynamics of the middle atmosphere. A simulation programme for calculation of Rayleigh-scattered signal, background level and noise was used to investigate the performance of the instrument. Various configurations of transmitters and receivers were evaluated. For the transmitter, laser diode arrays and solid state lasers were considered. The diode arrays were found suitable and two types of high power diode arrays were tested in the laboratory. A 20 bar array assembled using the bars-in-grooves technology was selected. It was operated in QCW mode with a pulse length of 450 μs, a pulse repetition rate of 135 Hz and an average optical power of 62 W at 805 ± 5 nm. It required a power supply giving 65 A at 42 V, active water cooling and a collimating lens. For the receiver, diodes and PMTs were considered. A large-area detector able to process photon rates of 106to 1010 s-1 was essential. An APD was selected due to the better quantum efficiency compared to the PMTs at 805 nm. It had a gain of 200 at 2.4 kV, and was cooled to -20°C to reduce the dark current to 1.5 nA and the rms-noise to 40 pA.
{"title":"A Rayleigh lidar on rockets for studies of the middle atmosphere","authors":"T. Eriksen, U. Hoppe, E. Thrane, T. Blix","doi":"10.1364/cleo_europe.1998.cmi6","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cmi6","url":null,"abstract":"Two new rocket-borne Rayleigh lidar experiments were developed at the Norwegian Defence Research Establishment and launched from Andøya Rocket Range in October 97 and January 98. The aim of the experiments were to measure the neutral atmosphere number density and to study the dynamics of the middle atmosphere. A simulation programme for calculation of Rayleigh-scattered signal, background level and noise was used to investigate the performance of the instrument. Various configurations of transmitters and receivers were evaluated. For the transmitter, laser diode arrays and solid state lasers were considered. The diode arrays were found suitable and two types of high power diode arrays were tested in the laboratory. A 20 bar array assembled using the bars-in-grooves technology was selected. It was operated in QCW mode with a pulse length of 450 μs, a pulse repetition rate of 135 Hz and an average optical power of 62 W at 805 ± 5 nm. It required a power supply giving 65 A at 42 V, active water cooling and a collimating lens. For the receiver, diodes and PMTs were considered. A large-area detector able to process photon rates of 106to 1010 s-1 was essential. An APD was selected due to the better quantum efficiency compared to the PMTs at 805 nm. It had a gain of 200 at 2.4 kV, and was cooled to -20°C to reduce the dark current to 1.5 nA and the rms-noise to 40 pA.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79157099","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cthh54
K. Shcherbin, S. Oaouiov, P. Poplavko
CdTe is studied intensively as promising material for the real time holographic recording in the near infrared because it ensures the largest gain factor as compared to the other photorefractive semiconductors. In this report we present the results of characterisation of photorefractive germanium doped CdTe crystals grown in different Ukrainian laboratories and compere the results with that known for vanadium doped CdTe [1].
{"title":"Photorefractivity of CdTe:Ge at 1.06 and 1.32 μm","authors":"K. Shcherbin, S. Oaouiov, P. Poplavko","doi":"10.1364/cleo_europe.1998.cthh54","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthh54","url":null,"abstract":"CdTe is studied intensively as promising material for the real time holographic recording in the near infrared because it ensures the largest gain factor as compared to the other photorefractive semiconductors. In this report we present the results of characterisation of photorefractive germanium doped CdTe crystals grown in different Ukrainian laboratories and compere the results with that known for vanadium doped CdTe [1].","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85875386","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cpd2.10
S. Kitson, R. Amos, P. Tapster, J. Rarity
We describe novel methods for making good quality colloidal crystals. We use polymethylmethacrylate (PMMA) spheres of diameter 0.8microns suspended in organic solvents between glass plates separated by about 10 microns. We have characterised the phase diagram in this confined system as a function of volume fraction and find that at volume concentrations beyond 49% a significant fraction of the suspended PMMA spheres are forced to crystallise into random close packed structures. The crystallite size is typically small (100microns) and the predominant structure is random close packed. This we confirm by single crystal light scattering measurements. We do find small areas of face centred cubic structure in these samples which we assume arises simply by chance stacking as the crystallites are typically only 10-15 layers thick. However the crystallite size can be increased simply by shearing the suspension during preparation. We also find conditions under which the formation of face centred cubic crystals can be preferential. We would present video footage of diffraction patterns formed during the shearing process where we can see clear evidence of the transition from random packing to FCC ordering.
{"title":"Making single crystal colloids for photonic bandgaps in the optical domain.","authors":"S. Kitson, R. Amos, P. Tapster, J. Rarity","doi":"10.1364/cleo_europe.1998.cpd2.10","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cpd2.10","url":null,"abstract":"We describe novel methods for making good quality colloidal crystals. We use polymethylmethacrylate (PMMA) spheres of diameter 0.8microns suspended in organic solvents between glass plates separated by about 10 microns. We have characterised the phase diagram in this confined system as a function of volume fraction and find that at volume concentrations beyond 49% a significant fraction of the suspended PMMA spheres are forced to crystallise into random close packed structures. The crystallite size is typically small (100microns) and the predominant structure is random close packed. This we confirm by single crystal light scattering measurements. We do find small areas of face centred cubic structure in these samples which we assume arises simply by chance stacking as the crystallites are typically only 10-15 layers thick. However the crystallite size can be increased simply by shearing the suspension during preparation. We also find conditions under which the formation of face centred cubic crystals can be preferential. We would present video footage of diffraction patterns formed during the shearing process where we can see clear evidence of the transition from random packing to FCC ordering.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75878736","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cff4
A. A. Nikitichev, A. Kornev, V. K. Stupnikov
The use of quasi-two-level laser medium in active mirror configuration seems to be the prospective approach to realisation of the high-power solid-state lasers. This approach was successfully applied to realisation of the diode pumped Yb:YAG laser. The low Stokes shift, thin active layer and longitudinal with respect to laser radiation thermal gradient provide the high specific generation power (3 kW/cm2) with high quality of radiation.
{"title":"2 µm Ho: YLF active mirror laser","authors":"A. A. Nikitichev, A. Kornev, V. K. Stupnikov","doi":"10.1364/cleo_europe.1998.cff4","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cff4","url":null,"abstract":"The use of quasi-two-level laser medium in active mirror configuration seems to be the prospective approach to realisation of the high-power solid-state lasers. This approach was successfully applied to realisation of the diode pumped Yb:YAG laser. The low Stokes shift, thin active layer and longitudinal with respect to laser radiation thermal gradient provide the high specific generation power (3 kW/cm2) with high quality of radiation.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76559181","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cthm2
M. Withford, D. J. W. Brown, R. Carman, J. Piper
Kinetically enhanced copper vapour lasers (KE-CVLs) have performance characteristics far exceeding those of conventional (elemental copper) devices [1,2]. For example, a 38mm diameter CVL normally producing only 65W when employing H2-Ne buffer gas mixtures produces >150W when kinetically enhanced. In addition, to the greatly increased repetition rate scaling characteristics of KE-CVLs, spatio-temporal gain characteristics are much more favourable for the extraction of high beam quality output from these devices.
{"title":"Optimisation of H2-HCl-Ne buffer gas mixtures used in kinetically enhanced copper vapour lasers","authors":"M. Withford, D. J. W. Brown, R. Carman, J. Piper","doi":"10.1364/cleo_europe.1998.cthm2","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthm2","url":null,"abstract":"Kinetically enhanced copper vapour lasers (KE-CVLs) have performance characteristics far exceeding those of conventional (elemental copper) devices [1,2]. For example, a 38mm diameter CVL normally producing only 65W when employing H2-Ne buffer gas mixtures produces >150W when kinetically enhanced. In addition, to the greatly increased repetition rate scaling characteristics of KE-CVLs, spatio-temporal gain characteristics are much more favourable for the extraction of high beam quality output from these devices.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76026168","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cthe3
N. Vuchkov, K. Temelkov, N. Sabotinov
Laser oscillation in ionized metal vapors in wide spectral range (from UV to IR) is known to date. Different type of gas discharges are used for metal ion laser excitation - continuous wave and pulsed positive column discharge; continuous wave and pulsed hollow cathode discharge; high frequency discharge and electron beam excitation. Each of these discharges has its advantages and drawbacks. An investigation is needed in metal vapor ion laser development involving new methods for excitation of this laser class.
{"title":"He-Hg+ and He-Cd+ Lasers","authors":"N. Vuchkov, K. Temelkov, N. Sabotinov","doi":"10.1364/cleo_europe.1998.cthe3","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthe3","url":null,"abstract":"Laser oscillation in ionized metal vapors in wide spectral range (from UV to IR) is known to date. Different type of gas discharges are used for metal ion laser excitation - continuous wave and pulsed positive column discharge; continuous wave and pulsed hollow cathode discharge; high frequency discharge and electron beam excitation. Each of these discharges has its advantages and drawbacks. An investigation is needed in metal vapor ion laser development involving new methods for excitation of this laser class.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75207704","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cthh110
B. Fracasso, P. Berthele, J. de Bougrenet de la Tocnaye
In the framework of optical transport networks based on wavelength division multiplexing, (WDM), one of the most critical elements is the optical cross-connect [1] (OXC). At the core of many cross-connect architectures is a space-switching stage, operating in the 1.55 telecom wavelength window. An important feature is that the device routing peformance must be polarisation insensitive, with moderate insertion loss and reconfiguration rates lower than the microsecond.
{"title":"Optimisation of a reconfigurable free-space fibre switch in the WDM 1,55 µm window","authors":"B. Fracasso, P. Berthele, J. de Bougrenet de la Tocnaye","doi":"10.1364/cleo_europe.1998.cthh110","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthh110","url":null,"abstract":"In the framework of optical transport networks based on wavelength division multiplexing, (WDM), one of the most critical elements is the optical cross-connect [1] (OXC). At the core of many cross-connect architectures is a space-switching stage, operating in the 1.55 telecom wavelength window. An important feature is that the device routing peformance must be polarisation insensitive, with moderate insertion loss and reconfiguration rates lower than the microsecond.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85881722","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.ctuc4
P. Schnitzer, M. Grabherr, R. Jäger, R. Michalzik, W. Schmid, K. Ebeling
Visible, red emitting vertical cavity surface emitting lasers (VCSELs) [1] in the wavelength regime between 650 and 780 nm are very attractive light sources in low cost optical interconnects with on polymer optical fibers (POFs). We have fabricated GaAs-based 780 nm emission wavelength VCSELs using solid source MBE and p-type Carbon doping. Single layer 30 nm thick oxide apertures provide current and optical confinement. We employ 120 μm core diameter POF (Toray PGR-FB 125) because conventional POFs have core diameters between 0.25 and 3 mm making them impractical for high density optical interconnects with transmitter and receiver array pitch sizes of 250 μm or less [2].
{"title":"GaAs VCSELs at λ = 780 nm for short distance polymer optical fiber data links at 2.5 Gb/s","authors":"P. Schnitzer, M. Grabherr, R. Jäger, R. Michalzik, W. Schmid, K. Ebeling","doi":"10.1364/cleo_europe.1998.ctuc4","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.ctuc4","url":null,"abstract":"Visible, red emitting vertical cavity surface emitting lasers (VCSELs) [1] in the wavelength regime between 650 and 780 nm are very attractive light sources in low cost optical interconnects with on polymer optical fibers (POFs). We have fabricated GaAs-based 780 nm emission wavelength VCSELs using solid source MBE and p-type Carbon doping. Single layer 30 nm thick oxide apertures provide current and optical confinement. We employ 120 μm core diameter POF (Toray PGR-FB 125) because conventional POFs have core diameters between 0.25 and 3 mm making them impractical for high density optical interconnects with transmitter and receiver array pitch sizes of 250 μm or less [2].","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83912346","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}
Pub Date : 1998-01-01DOI: 10.1364/cleo_europe.1998.cpd2.1
G. Love
Adaptive optics (AO) is an emerging technology used to correct aberrations in optical systems. It achieves this by spatial and temporally phase modulating the light, as opposed to image processing techniques which aim to deconvolve aberrations once an image has been recorded.
{"title":"Adaptive optical applications of electro-optic devices","authors":"G. Love","doi":"10.1364/cleo_europe.1998.cpd2.1","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cpd2.1","url":null,"abstract":"Adaptive optics (AO) is an emerging technology used to correct aberrations in optical systems. It achieves this by spatial and temporally phase modulating the light, as opposed to image processing techniques which aim to deconvolve aberrations once an image has been recorded.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82436989","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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