Sayuri Ban, A. Hosoki, M. Nishiyama, A. Seki, Kazuhiro Watanabe
Optical fiber oxygen sensors have attractive attentions such as no oxygen consume, thin size, light weight, flexibility, and immunity to electromagnetic interference. Ruthenium (Ru) complexes are known as luminescent materials whose luminescent light is quenched depending on oxygen concentrations when concentrations of Ru complexes are fixed. They emit phosphorescence with the wavelength of around 620 nm as exited light with the wavelength of 450 nm is irradiated into Ru complexes. As a result, phosphorescence is quenched depending on oxygen concentrations. Conventional optical fiber oxygen sensors have employed large core-diameter such as 1000 μm in order to obtain quenching abundantly, hence they have large transmission loss. Therefore, they have little practicability in the case of remote monitoring system, for example undersea explorations. In this paper, we have successfully developed a novel optical fiber oxygen sensor with transmission GI multi-mode fiber whose core diameter is 62.5 μm and cladding diameter is 125 μm. The sensing portion was fabricated on an end of the fiber with porous composite membranes which is made by glass beads and polyallylamine in Layer-by-Layer technique. The composite membranes immobilized Ru complexes. In experiments, in order to investigate characteristics of the number of layers for porous composite membranes, we tested several kinds of sensors having such as 5-, 50- and 125-layers and confirmed phosphorescent intensity and change of phosphorescence against existence of oxygen. As a result, 5-layer and 50-layer sensors showed best sensitivity and reproducibility.
{"title":"Optical fiber oxygen sensor using layer-by-layer stacked porous composite membranes","authors":"Sayuri Ban, A. Hosoki, M. Nishiyama, A. Seki, Kazuhiro Watanabe","doi":"10.1117/12.2212137","DOIUrl":"https://doi.org/10.1117/12.2212137","url":null,"abstract":"Optical fiber oxygen sensors have attractive attentions such as no oxygen consume, thin size, light weight, flexibility, and immunity to electromagnetic interference. Ruthenium (Ru) complexes are known as luminescent materials whose luminescent light is quenched depending on oxygen concentrations when concentrations of Ru complexes are fixed. They emit phosphorescence with the wavelength of around 620 nm as exited light with the wavelength of 450 nm is irradiated into Ru complexes. As a result, phosphorescence is quenched depending on oxygen concentrations. Conventional optical fiber oxygen sensors have employed large core-diameter such as 1000 μm in order to obtain quenching abundantly, hence they have large transmission loss. Therefore, they have little practicability in the case of remote monitoring system, for example undersea explorations. In this paper, we have successfully developed a novel optical fiber oxygen sensor with transmission GI multi-mode fiber whose core diameter is 62.5 μm and cladding diameter is 125 μm. The sensing portion was fabricated on an end of the fiber with porous composite membranes which is made by glass beads and polyallylamine in Layer-by-Layer technique. The composite membranes immobilized Ru complexes. In experiments, in order to investigate characteristics of the number of layers for porous composite membranes, we tested several kinds of sensors having such as 5-, 50- and 125-layers and confirmed phosphorescent intensity and change of phosphorescence against existence of oxygen. As a result, 5-layer and 50-layer sensors showed best sensitivity and reproducibility.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125088994","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}
M. Karppinen, A. Tanskanen, V. Heikkinen, P. Myöhänen, N. Salminen, J. Ollila, O. Tapaninen, P. Westbergh, J. Gustavsson, A. Larsson, R. Safaisini, R. King, M. Ko, D. Kissinger, A. Çağrı Ulusoy, T. Taunay, L. Bansal, L. Grüner-Nielsen, E. Kehayas, J. Edmunds, L. Stampoulidis
Multicore fiber enables a parallel optic data link with a single optical fiber, thus providing an attractive way to increase the total throughput and the integration density of the interconnections. We study and present photonics integration technologies and optical coupling approaches for multicore transmitter and receiver subassemblies. Such optical engines are implemented and characterized using multimode 6-core fibers and multicore-optimized active devices: 850-nm VCSEL and PD arrays with circular layout and multi-channel driver and receiver ICs. They are developed for bit-rates of 25 Gbps/channel and beyond, i.e. <150 Gbps per fiber, and also optimized for ruggedized transceivers with extended operation temperature range, for harsh environment applications, including space.
{"title":"Integration of 150 Gbps/fiber optical engines based on multicore fibers and 6-channel VCSELs and PDs","authors":"M. Karppinen, A. Tanskanen, V. Heikkinen, P. Myöhänen, N. Salminen, J. Ollila, O. Tapaninen, P. Westbergh, J. Gustavsson, A. Larsson, R. Safaisini, R. King, M. Ko, D. Kissinger, A. Çağrı Ulusoy, T. Taunay, L. Bansal, L. Grüner-Nielsen, E. Kehayas, J. Edmunds, L. Stampoulidis","doi":"10.1117/12.2214555","DOIUrl":"https://doi.org/10.1117/12.2214555","url":null,"abstract":"Multicore fiber enables a parallel optic data link with a single optical fiber, thus providing an attractive way to increase the total throughput and the integration density of the interconnections. We study and present photonics integration technologies and optical coupling approaches for multicore transmitter and receiver subassemblies. Such optical engines are implemented and characterized using multimode 6-core fibers and multicore-optimized active devices: 850-nm VCSEL and PD arrays with circular layout and multi-channel driver and receiver ICs. They are developed for bit-rates of 25 Gbps/channel and beyond, i.e. <150 Gbps per fiber, and also optimized for ruggedized transceivers with extended operation temperature range, for harsh environment applications, including space.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126839861","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}
Yi Zou, S. Chakravarty, Chi-Jui Chung, Ray T. Chen
Ultracompact thermooptically tuned photonic crystal waveguide (PCW) based Mach–Zehnder interferometers (MZIs) working in silicon-on-sapphire in mid-infrared regime have been proposed and demonstrated. We designed and fabricated a PCW based silicon thermo-optic (TO) switch operating at 3.43 μm. Both steady-state and transient thermal analyses were performed to evaluate the thermal performance of the TO MZIs. The required π phase shift between the two arms of the MZI has been successfully achieved within an 80 μm interaction distance. The maximum modulation depth of 74% was demonstrated for switching power of 170 mW.
{"title":"Miniature mid-infrared thermooptic switch with photonic crystal waveguide based silicon-on-sapphire Mach–Zehnder interferometers","authors":"Yi Zou, S. Chakravarty, Chi-Jui Chung, Ray T. Chen","doi":"10.1117/12.2214440","DOIUrl":"https://doi.org/10.1117/12.2214440","url":null,"abstract":"Ultracompact thermooptically tuned photonic crystal waveguide (PCW) based Mach–Zehnder interferometers (MZIs) working in silicon-on-sapphire in mid-infrared regime have been proposed and demonstrated. We designed and fabricated a PCW based silicon thermo-optic (TO) switch operating at 3.43 μm. Both steady-state and transient thermal analyses were performed to evaluate the thermal performance of the TO MZIs. The required π phase shift between the two arms of the MZI has been successfully achieved within an 80 μm interaction distance. The maximum modulation depth of 74% was demonstrated for switching power of 170 mW.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120974650","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}
M. Meinig, S. Kurth, M. Seifert, K. Hiller, J. Wecker, M. Ebermann, N. Neumann, T. Gessner
This report presents recent advances in the design and fabrication of a tunable Fabry-Pérot interferometer (FPI) with subwavelength grating (SWG) reflectors, as well as measurement results and applications. The FPI is designed as wavelength selecting element for highly miniaturized mid-wave infrared spectrometers. The optical resonator of the FPI is built between two highly reflecting mirrors. The mirrors are integrated in a supporting MEMS structure with one electrostatically movable and one fixed mirror carrier. The FPI is fabricated in a bulk micromachining batch process on wafer level from two silicon substrates. The substrates are bonded together with an intermediate SU-8 layer. The reflectors are made of aluminum subwavelength gratings, structured on a thin LP-Si3N4 membrane by nanoimprint lithography. The subwavelength structures build a frequency selective surface with high reflectance and low absorbance in a defined spectral range. Simulations and optimization of the design were done using finite element method with a 3D EM frequency domain solver. Comparison of simulation results and measurements of fabricated reflectors and FPIs are in very good agreement. The FPIs are used in the 5th interference order and can be tuned from 3.5 μm to 2.9 μm electrically. The measured maximum transmittance is between 70 % and 50 % and the measured FWHM bandwidth is lower than 50 nm. The new subwavelength grating reflectors can be integrated in a MEMS batch process more cost-efficient than previously used reflectors of dielectric layer stacks.
{"title":"Tunable Fabry-Pérot interferometer with subwavelength grating reflectors for MWIR microspectrometers","authors":"M. Meinig, S. Kurth, M. Seifert, K. Hiller, J. Wecker, M. Ebermann, N. Neumann, T. Gessner","doi":"10.1117/12.2213647","DOIUrl":"https://doi.org/10.1117/12.2213647","url":null,"abstract":"This report presents recent advances in the design and fabrication of a tunable Fabry-Pérot interferometer (FPI) with subwavelength grating (SWG) reflectors, as well as measurement results and applications. The FPI is designed as wavelength selecting element for highly miniaturized mid-wave infrared spectrometers. The optical resonator of the FPI is built between two highly reflecting mirrors. The mirrors are integrated in a supporting MEMS structure with one electrostatically movable and one fixed mirror carrier. The FPI is fabricated in a bulk micromachining batch process on wafer level from two silicon substrates. The substrates are bonded together with an intermediate SU-8 layer. The reflectors are made of aluminum subwavelength gratings, structured on a thin LP-Si3N4 membrane by nanoimprint lithography. The subwavelength structures build a frequency selective surface with high reflectance and low absorbance in a defined spectral range. Simulations and optimization of the design were done using finite element method with a 3D EM frequency domain solver. Comparison of simulation results and measurements of fabricated reflectors and FPIs are in very good agreement. The FPIs are used in the 5th interference order and can be tuned from 3.5 μm to 2.9 μm electrically. The measured maximum transmittance is between 70 % and 50 % and the measured FWHM bandwidth is lower than 50 nm. The new subwavelength grating reflectors can be integrated in a MEMS batch process more cost-efficient than previously used reflectors of dielectric layer stacks.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116203392","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}
Recently, double-clad crystalline fiber waveguides (CFWs), consisting of single crystalline or ceramic RE3+:YAG cores of square cross section and inner claddings of either undoped or laser-inactive-ion-doped YAG and outer claddings of sapphire, have been successfully demonstrated. These waveguides, manufactured by an Adhesive-Free Bonding (AFB®) technique, can be precisely engineered and fabricated with predictable beam propagation behavior. In this work, with high power laser designs in mind, minimum thicknesses for inner cladding are derived for different core cross sections and refractive index differences between the core and inner cladding and sapphire as outer cladding material for common laser core dopants such as Nd3+, Yb3+, Er3+, Tm3+ and Ho3+. All designs are intended to use high NA high power laser diode pumping to obtain high power intrinsically single transverse mode laser output. The obtained data are applicable to any crystalline fiber waveguide design, regardless of fabrication technique. As an example, a CFW with 40 μm × 40 μm 4% Tm:YAG core, 5% Yb:YAG inner cladding, and sapphire outer cladding was calculated to be intrinsically single transverse mode, with the minimum inner cladding width of 21.7 μm determined by the effective index technique [1].
{"title":"Design of intrinsically single-mode double clad crystalline fiber waveguides for high power lasers","authors":"Da Li, Pengda Hong, S. Meissner, H. Meissner","doi":"10.1117/12.2213453","DOIUrl":"https://doi.org/10.1117/12.2213453","url":null,"abstract":"Recently, double-clad crystalline fiber waveguides (CFWs), consisting of single crystalline or ceramic RE3+:YAG cores of square cross section and inner claddings of either undoped or laser-inactive-ion-doped YAG and outer claddings of sapphire, have been successfully demonstrated. These waveguides, manufactured by an Adhesive-Free Bonding (AFB®) technique, can be precisely engineered and fabricated with predictable beam propagation behavior. In this work, with high power laser designs in mind, minimum thicknesses for inner cladding are derived for different core cross sections and refractive index differences between the core and inner cladding and sapphire as outer cladding material for common laser core dopants such as Nd3+, Yb3+, Er3+, Tm3+ and Ho3+. All designs are intended to use high NA high power laser diode pumping to obtain high power intrinsically single transverse mode laser output. The obtained data are applicable to any crystalline fiber waveguide design, regardless of fabrication technique. As an example, a CFW with 40 μm × 40 μm 4% Tm:YAG core, 5% Yb:YAG inner cladding, and sapphire outer cladding was calculated to be intrinsically single transverse mode, with the minimum inner cladding width of 21.7 μm determined by the effective index technique [1].","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121354156","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}
Power scaling analysis based on the model by Dawson et al. [1,2] for circular core fibers has been applied to estimating power scaling of crystalline fiber waveguides (CFWs) with RE3+ doped single crystalline or ceramic YAG (RE=rare earth: Yb, Er, Tm and Ho). Power scaling limits include stimulated Brillouin scattering, thermal lensing effect, and limits to coupling of pump light into CFWs. The CFW designs we have considered consist, in general, of a square doped RE3+:YAG core, an inner cladding of either undoped or laser-inactive-ion-doped YAG and an outer cladding of sapphire. The presented data have been developed for the structures fabricated using the Adhesive-Free Bonding (AFB®) technique, but the results should be essentially independent of fabrication technique, assuming perfect core/inner cladding/outer cladding interfaces. Hard power scaling limits exist for a specific CFW design and are strongly based on the physical constants of the material and its spectroscopic specifics. For example, power scaling limit was determined as ~16 kW for 2.5% ceramic Yb:YAG/YAG (core material/inner cladding material) at fiber length of 1.7 m and core diameter of 69 μm. Considering the present manufacturing limit for CFW length to be, e.g., 0.5 m, the actual maximum output power will be limited to ~4.4 kW for a Yb:YAG/YAG CFW. Power limit estimates have also been computed for Er3+, Tm3+ and Ho3+doped core based CFWs.
基于Dawson等人[1,2]的圆芯光纤模型的功率缩放分析已被应用于估算含有RE3+掺杂单晶或陶瓷YAG (RE=稀土:Yb, Er, Tm和Ho)的晶体光纤波导(cfw)的功率缩放。功率缩放限制包括受激布里渊散射、热透镜效应和泵浦光耦合到cfw的限制。一般来说，我们考虑的CFW设计包括一个方形掺杂的RE3+:YAG核心，一个未掺杂或激光不活跃离子掺杂的YAG的内包层和一个蓝宝石的外包层。本文所提供的数据是针对使用无粘合剂粘合(AFB®)技术制造的结构而开发的，但假设完美的核心/内包层/外包层界面，结果应该基本上独立于制造技术。特定的CFW设计存在硬功率缩放限制，并且在很大程度上取决于材料的物理常数及其光谱特性。例如，当光纤长度为1.7 m，纤芯直径为69 μm时，2.5%陶瓷Yb:YAG/YAG(芯材/内包层材料)的功率缩放极限为~16 kW。考虑到目前对CFW长度的制造限制，例如0.5 m，对于Yb:YAG/YAG CFW，实际最大输出功率将限制在~4.4 kW。我们还计算了Er3+、Tm3+和Ho3+掺杂核基cfw的功率极限估计。
{"title":"Power scaling estimate of crystalline fiber waveguides with rare earth doped YAG cores","authors":"Da Li, Pengda Hong, S. Meissner, H. Meissner","doi":"10.1117/12.2213474","DOIUrl":"https://doi.org/10.1117/12.2213474","url":null,"abstract":"Power scaling analysis based on the model by Dawson et al. [1,2] for circular core fibers has been applied to estimating power scaling of crystalline fiber waveguides (CFWs) with RE3+ doped single crystalline or ceramic YAG (RE=rare earth: Yb, Er, Tm and Ho). Power scaling limits include stimulated Brillouin scattering, thermal lensing effect, and limits to coupling of pump light into CFWs. The CFW designs we have considered consist, in general, of a square doped RE3+:YAG core, an inner cladding of either undoped or laser-inactive-ion-doped YAG and an outer cladding of sapphire. The presented data have been developed for the structures fabricated using the Adhesive-Free Bonding (AFB®) technique, but the results should be essentially independent of fabrication technique, assuming perfect core/inner cladding/outer cladding interfaces. Hard power scaling limits exist for a specific CFW design and are strongly based on the physical constants of the material and its spectroscopic specifics. For example, power scaling limit was determined as ~16 kW for 2.5% ceramic Yb:YAG/YAG (core material/inner cladding material) at fiber length of 1.7 m and core diameter of 69 μm. Considering the present manufacturing limit for CFW length to be, e.g., 0.5 m, the actual maximum output power will be limited to ~4.4 kW for a Yb:YAG/YAG CFW. Power limit estimates have also been computed for Er3+, Tm3+ and Ho3+doped core based CFWs.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129451894","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}
N. Prasad, A. Tracy, S. Vetorino, R. Higgins, R. Sibell
This paper describes an innovative, compact and eyesafe coherent lidar system developed for use in wind and wake vortex sensing applications. This advanced lidar system is field ruggedized with reduced size, weight, and power consumption (SWaP) configured based on an all-fiber and modular architecture. The all-fiber architecture is developed using a fiber seed laser that is coupled to uniquely configured fiber amplifier modules and associated photonic elements including an integrated 3D scanner. The scanner provides user programmable continuous 360 degree azimuth and 180 degree elevation scan angles. The system architecture eliminates free-space beam alignment issues and allows plug and play operation using graphical user interface software modules. Besides its all fiber architecture, the lidar system also provides pulsewidth agility to aid in improving range resolution. Operating at 1.54 microns and with a PRF of up to 20 KHz, the wind lidar is air cooled with overall dimensions of 30” x 46” x 60” and is designed as a Class 1 system. This lidar is capable of measuring wind velocities greater than 120 +/- 0.2 m/s over ranges greater than 10 km and with a range resolution of less than 15 m. This compact and modular system is anticipated to provide mobility, reliability, and ease of field deployment for wind and wake vortex measurements. The current lidar architecture is amenable for trace gas sensing and as such it is being evolved for airborne and space based platforms. In this paper, the key features of wind lidar instrumentation and its functionality are discussed followed by results of recent wind forecast measurements on a wind farm.
{"title":"Innovative fiber-laser architecture-based compact wind lidar","authors":"N. Prasad, A. Tracy, S. Vetorino, R. Higgins, R. Sibell","doi":"10.1117/12.2218226","DOIUrl":"https://doi.org/10.1117/12.2218226","url":null,"abstract":"This paper describes an innovative, compact and eyesafe coherent lidar system developed for use in wind and wake vortex sensing applications. This advanced lidar system is field ruggedized with reduced size, weight, and power consumption (SWaP) configured based on an all-fiber and modular architecture. The all-fiber architecture is developed using a fiber seed laser that is coupled to uniquely configured fiber amplifier modules and associated photonic elements including an integrated 3D scanner. The scanner provides user programmable continuous 360 degree azimuth and 180 degree elevation scan angles. The system architecture eliminates free-space beam alignment issues and allows plug and play operation using graphical user interface software modules. Besides its all fiber architecture, the lidar system also provides pulsewidth agility to aid in improving range resolution. Operating at 1.54 microns and with a PRF of up to 20 KHz, the wind lidar is air cooled with overall dimensions of 30” x 46” x 60” and is designed as a Class 1 system. This lidar is capable of measuring wind velocities greater than 120 +/- 0.2 m/s over ranges greater than 10 km and with a range resolution of less than 15 m. This compact and modular system is anticipated to provide mobility, reliability, and ease of field deployment for wind and wake vortex measurements. The current lidar architecture is amenable for trace gas sensing and as such it is being evolved for airborne and space based platforms. In this paper, the key features of wind lidar instrumentation and its functionality are discussed followed by results of recent wind forecast measurements on a wind farm.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129860078","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}
G. Skolianos, Arushi Arora, M. Bernier, M. Digonnet
We report a new generation of slow-light FBG strain sensor with a strain resolution (or minimum detectable strain) as low as 30 fepsilon/√Hz at 30 kHz, which is one order of magnitude lower than the record held by the previous generation. This sensor has an ultra-stable output (no drift in 4 days) and is capable of resolving an absolute strain of ~250 attostrains by integrating its output for ~8 hours, which is also a new record for an FBG fiber sensor. These improvements were accomplished by first maximizing the slope of the slow-light resonances, and hence the strain sensitivity. To this end the apodized FBG was written in a deuterium-loaded fiber with a femtosecond infrared laser, then thermally annealed. The three main sources of noise in the sensor system were also carefully reduced. The dominant source of noise, laser frequency noise, was reduced by interrogating the FBG with an ultra-stable laser (linewidth under 200 Hz) with a low intensity noise. The phase noise was minimized by selecting the proper FBG length (~25 mm). When used as an acoustic sensor, the same grating had a measured average pressure resolution of 50 μPa/√Hz between 3 kHz and 6 kHz, one order of magnitude lower than the previous lowest reported value for an FBG sensor.
{"title":"Measuring attostrains in a slow-light fiber Bragg grating","authors":"G. Skolianos, Arushi Arora, M. Bernier, M. Digonnet","doi":"10.1117/12.2220219","DOIUrl":"https://doi.org/10.1117/12.2220219","url":null,"abstract":"We report a new generation of slow-light FBG strain sensor with a strain resolution (or minimum detectable strain) as low as 30 fepsilon/√Hz at 30 kHz, which is one order of magnitude lower than the record held by the previous generation. This sensor has an ultra-stable output (no drift in 4 days) and is capable of resolving an absolute strain of ~250 attostrains by integrating its output for ~8 hours, which is also a new record for an FBG fiber sensor. These improvements were accomplished by first maximizing the slope of the slow-light resonances, and hence the strain sensitivity. To this end the apodized FBG was written in a deuterium-loaded fiber with a femtosecond infrared laser, then thermally annealed. The three main sources of noise in the sensor system were also carefully reduced. The dominant source of noise, laser frequency noise, was reduced by interrogating the FBG with an ultra-stable laser (linewidth under 200 Hz) with a low intensity noise. The phase noise was minimized by selecting the proper FBG length (~25 mm). When used as an acoustic sensor, the same grating had a measured average pressure resolution of 50 μPa/√Hz between 3 kHz and 6 kHz, one order of magnitude lower than the previous lowest reported value for an FBG sensor.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129661001","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}
Near resonant pumping of solid-state lasers offers the potential for high efficiency and minimal thermal loading. These lasers inherently operate in the regime where fluorescent cooling plays an important role. Here a model is developed to optimize efficiency and minimize heating for these laser systems. The model incorporates realistic background absorption and excitation quenching. Beyond the conventional laser modeling, this s includes both radiative cooling and fluorescence trapping. The model is illustrated with simulations of Yb:YAG lasers.
{"title":"Realistic modeling of low quantum defect lasers","authors":"S. Bowman","doi":"10.1117/12.2213119","DOIUrl":"https://doi.org/10.1117/12.2213119","url":null,"abstract":"Near resonant pumping of solid-state lasers offers the potential for high efficiency and minimal thermal loading. These lasers inherently operate in the regime where fluorescent cooling plays an important role. Here a model is developed to optimize efficiency and minimize heating for these laser systems. The model incorporates realistic background absorption and excitation quenching. Beyond the conventional laser modeling, this s includes both radiative cooling and fluorescence trapping. The model is illustrated with simulations of Yb:YAG lasers.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"338 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133985489","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}
H. Subbaraman, Zeyu Pan, Cheng Zhang, Qiaochu Li, L. Guo, Ray T. Chen
Polymer photonic device fabrication usually relies on the utilization of clean-room processes, including photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which are expensive and are limited to areas as large as a wafer. Utilizing a novel and a scalable printing process involving ink-jet printing and imprinting, we have fabricated polymer based photonic interconnect components, such as electro-optic polymer based modulators and ring resonator switches, and thermo-optic polymer switch based delay networks and demonstrated their operation. Specifically, a modulator operating at 15MHz and a 2-bit delay network providing up to 35.4ps are presented. In this paper, we also discuss the manufacturing challenges that need to be overcome in order to make roll-to-roll manufacturing practically viable. We discuss a few manufacturing challenges, such as inspection and quality control, registration, and web control, that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. We have overcome these challenges, and currently utilizing our inhouse developed hardware and software tools, <10μm alignment accuracy at a 5m/min is demonstrated. Such a scalable roll-to-roll manufacturing scheme will enable the development of unique optoelectronic devices which can be used in a myriad of different applications, including communication, sensing, medicine, security, imaging, energy, lighting etc.
{"title":"Printed polymer photonic devices for optical interconnect systems","authors":"H. Subbaraman, Zeyu Pan, Cheng Zhang, Qiaochu Li, L. Guo, Ray T. Chen","doi":"10.1117/12.2213373","DOIUrl":"https://doi.org/10.1117/12.2213373","url":null,"abstract":"Polymer photonic device fabrication usually relies on the utilization of clean-room processes, including photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which are expensive and are limited to areas as large as a wafer. Utilizing a novel and a scalable printing process involving ink-jet printing and imprinting, we have fabricated polymer based photonic interconnect components, such as electro-optic polymer based modulators and ring resonator switches, and thermo-optic polymer switch based delay networks and demonstrated their operation. Specifically, a modulator operating at 15MHz and a 2-bit delay network providing up to 35.4ps are presented. In this paper, we also discuss the manufacturing challenges that need to be overcome in order to make roll-to-roll manufacturing practically viable. We discuss a few manufacturing challenges, such as inspection and quality control, registration, and web control, that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. We have overcome these challenges, and currently utilizing our inhouse developed hardware and software tools, <10μm alignment accuracy at a 5m/min is demonstrated. Such a scalable roll-to-roll manufacturing scheme will enable the development of unique optoelectronic devices which can be used in a myriad of different applications, including communication, sensing, medicine, security, imaging, energy, lighting etc.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"299 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133842240","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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