The nano-particle-based planar laser scattering （NPLS） technique is used to measure the density distribution in the supersonic mixing layer of the convective Mach number 0.12, and the optical path difference （OPL）...The nano-particle-based planar laser scattering （NPLS） technique is used to measure the density distribution in the supersonic mixing layer of the convective Mach number 0.12, and the optical path difference （OPL）, which is quite crucial for the study of aero-optics, is obtained by post processing. Based on the high spatiotemporal resolutions of the NPLS, the structure of the OPL is ana]ysed using wavelet methods. The coherent structures of the OPL are extracted using three methods, including the methods of thresholding the coefficients of the orthogonal wavelet transform and the wavelet packet transform, and preserving a number of wavelet packet coefficients with the largest amplitudes determined by the entropy dimension. Their performances are compared, and the method using the wavelet packet is the best. Based on the viewpoint of multifractals, we study the OPL by the wavelet transform maxima method （WTMM）, and the result indicates that its scaling behaviour is evident.展开更多
A simple method is applied to calculating the optical path difference （OPD） of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displ...A simple method is applied to calculating the optical path difference （OPD） of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displacement （LD） of Savart polariscope under non-ideal conditions are obtained exactly. The variations of OPD and LD are simulated, and some important conclusions are obtained when the optical axis directions have an identical tolerance of ／pm 1^{{／circ}}. An application example is given that the tolerances of optical axis directions are gained according to the spectral resolution tolerances of the stationary polarization interference imaging spectrometer （SPIIS）. Several approximate formulae are obtained for explaining some conclusions above. The work provides a theoretical guidance for the optic design, crystal processing, installation and debugging, data analysis and spectral reconstruction of the SPIIS.展开更多
To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coa...To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.展开更多
A fold optical path is utilized to capture and launch atoms in the atomic fountain. This improved technique reduces the laser power needed by 60 percent, facilitates suppression of the laser power fluctuations, and le...A fold optical path is utilized to capture and launch atoms in the atomic fountain. This improved technique reduces the laser power needed by 60 percent, facilitates suppression of the laser power fluctuations, and leads to a more simple and stable system.展开更多
Based on the measurement of one-dimensional （1D） optical path difference （OPD） of the supersonic turbulent bound- ary layer, an analytical form for the power spectrum of the two-dimensional （2D） OPD is obtained ...Based on the measurement of one-dimensional （1D） optical path difference （OPD） of the supersonic turbulent bound- ary layer, an analytical form for the power spectrum of the two-dimensional （2D） OPD is obtained with its structure function and under the locally homogeneous isotropic assumption. The universality of this spectrum is argued, and its validity is checked by the comparison with experimental result. The potential applications of this model in theoretical and numerical studies are emphasized. Another contribution of this work is around the application of correlation function to analyzing the statistics of OPD. Based on our results and other results published elsewhere, we show that the OPD is often not stationary, and one should be cautious about using this tool.展开更多
We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD ...We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.展开更多
Instrument drifts introduce additional phase errors into atmospheric wind measurement of Doppler asymmetric spatial heterodyne spectroscopy (DASH). Aiming at the phase sensitivity of DASH to instrument drifts, in this...Instrument drifts introduce additional phase errors into atmospheric wind measurement of Doppler asymmetric spatial heterodyne spectroscopy (DASH). Aiming at the phase sensitivity of DASH to instrument drifts, in this paper we calculate the optical path difference (OPD) and present an accurate formula of DASH interferogram. By controlling variables in computational ray-tracing simulations and laboratory experiments, it is indicated that initial phase is directly determined by incident wavenumber, OPD offset and field of view (FOV). Accordingly, it is indicated that retrieved phase of DASH is sensitive to slight structural change caused by instrument drift, which provides the proof of necessary-to-track and -correct phase errors from instrument drifts.展开更多
In this paper, the light trapping characteristics of glass substrate with hemisphere pit （HP） arrays in thin film Si solar cells are theoretically studied via a numerical approach. It is found that the HP glass subs...In this paper, the light trapping characteristics of glass substrate with hemisphere pit （HP） arrays in thin film Si solar cells are theoretically studied via a numerical approach. It is found that the HP glass substrate has good antireflection properties. Its surface reflectance can be reduced by - 50% compared with planar glass. The HP arrays can make the unabsorbed light return to the absorbing layer of solar cells, and the ratio of second absorption approximately equals 30%. Thus, the glass substrate with the hemisphere pit arrays （HP glass） can effectively reduce the total reflectivity of a solar celt from 20% to 13%. The lip glass can also prolong the optical path length. The numerical results show that the total optical path length of the thin film Si solar cell covered with the HP glass increases from 2ω to 409. These results are basically consistent with the experimental results.展开更多
A static polarization interferometer for measuring upper atmospheric winds is presented, based on two Savart plates with their optical axes perpendicular to each other. The principle and characteristics of the interfe...A static polarization interferometer for measuring upper atmospheric winds is presented, based on two Savart plates with their optical axes perpendicular to each other. The principle and characteristics of the interferometer are described. The interferometer with a wide field of view can offer a stable benchmark optical path difference over a specified spectral region of 0.55-0.63μm because there are no quarter wave plates. Since the instrument employs a straight line common-path configuration but without moving parts and slits, it is very compact, simple, inherently robust and has high throughput. The paper is limited to a theoretical analysis.展开更多
Design method and procedures of computer-generated hologram （CGH） used for aspheric test are in- troduced in detail. For CGH phase calculation, virtual medium which has zero refractive index at given wavelength is u...Design method and procedures of computer-generated hologram （CGH） used for aspheric test are in- troduced in detail. For CGH phase calculation, virtual medium which has zero refractive index at given wavelength is used to model ideal aspheric wavefront. Reflective Fresnel zones located in a ring area concentric to the CGH structure is designed to reduce or eliminate alignment errors. Substrate figure error, pattern distortion, etching and duty cycle variations that influence the reconstructed wavefront are quantitatively analyzed in theory and corresponding error equations are obtained to guide the tolerance distribution during CGH fabricating. A design example is given and the uncertainty of t achieves λ20.展开更多
A seed laser oscillating at different frequencies is proved to have the potential to mitigate the stimulated Brillouin scattering（SBS） effect in a fiber amplifier,which may increase the emission power of a coherent ...A seed laser oscillating at different frequencies is proved to have the potential to mitigate the stimulated Brillouin scattering（SBS） effect in a fiber amplifier,which may increase the emission power of a coherent beam combination（CBC） system greatly.In this study,a basic mathematical model describing the multi-wavelength CBC is proposed on the fundamentals of CBC.A useful method for estimating the combination effect and analysing the feasibility and the validity of the multi-wavelength coherent combination is provided.In the numerical analysis,accordant results with four-wavelength four-channel CBC experiments are obtained.Through calculations of some examples with certain spectra,the unanticipated excellent combination effect with a few frequencies involved is explained,and the dependence of the combination effect on the variance of the amplifier chain length and the channel number is clarified.展开更多
Abstract: In order to solve the problem of high precision, complete electric insulating detection of the pressure measuring system, we have developed the three - beam interferometer. In this paper, the operation princ...Abstract: In order to solve the problem of high precision, complete electric insulating detection of the pressure measuring system, we have developed the three - beam interferometer. In this paper, the operation principle, structure of the system and measuring results are given.展开更多
In strip surface quality inspection systems based on the machine vision detection technology ,image quality is a key factor affecting the final detection performance. Composite imaging methods, such as bright and dark...In strip surface quality inspection systems based on the machine vision detection technology ,image quality is a key factor affecting the final detection performance. Composite imaging methods, such as bright and dark field imaging or reflection and transmission imaging, can reveal more information by emphasizing different image aspects. Defect detection rates and defect recognition accuracy can be improved by integrating and matching information from different image acquisition settings. Practical application shows that transmission and reflection composite imaging can improve the imaging quality of penetrative defects, while bright and dark field composite imaging can enhance imaging of defects such as color deviation and stains.展开更多
In this study,we present a dual-Fizeau-interferometer-based high-speed and wide-range fiber-optic Fabry-Perot(F-P)demodulation system.We employ two Fizeau interferometers with air cavity thickness satisfying the quadr...In this study,we present a dual-Fizeau-interferometer-based high-speed and wide-range fiber-optic Fabry-Perot(F-P)demodulation system.We employ two Fizeau interferometers with air cavity thickness satisfying the quadrature requirement to increase the demodulation speed and broaden the demodulation range in order to address the issues of the existing fiber F-P demodulation system's sluggish demodulation rate and limited range.In order to investigate the demodulation properties of the dual-Fizeau-interferometer-based demodulation system,we derive and create a theoretical model of the system.The theoretical model,which primarily consists of the structural design of the interferometer and the study of the center wavelength of the light sources and their bandwidth selection,is used to construct the optical structure of the demodulation system.According to the calculation results,the demodulated signal exhibits the best contrast ratio when the two light sources'respective center wavelengths are 780nm and 850nm,and their bandwidths are 28nm and 30 nm.Finally,we finish evaluating the demodulation system's demodulation performance,parameter calibration,and assembly debugging.The test results demonstrate the constant operation of the demodulation system,an update rate of 100kHz,a demodulation range of 4.74μm,and a cavity length resolution of approximately 5 nm.Additionally,the system can perform high speed demodulation thanks to the light emitting diode's(LED's)nanosecond level switching speed and the usage of a single point detector.展开更多
Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwav...Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwave photonics filtering[1–3],arbitrary generation[4–6]and analog to digital conversion[7]。展开更多
In the field of absorption spectroscopy,the multipass cell[MPC]is one of the key elements.It has the advantages of simple structure,easy adjustment,and high spectral coverage,which is an effective way to improve the d...In the field of absorption spectroscopy,the multipass cell[MPC]is one of the key elements.It has the advantages of simple structure,easy adjustment,and high spectral coverage,which is an effective way to improve the detection sensitivity of gas sensing systems such as tunable diode laser absorption spectroscopy.This invited paper summarizes the design theory and the research results of some mainstream types of MPCs based on two mirrors and more than two mirrors in recent years,and briefly introduces the application of some processed products.The design theory of modified ABCD matrix and vector reflection principle are explained in detail.Finally,trends in its development are predicted.展开更多
Recent developments in spectral white-light interferometry(WLI)are reviewed.Firstly,the techniques for obtaining optical spectrum are introduced.Secondly,some novel measurement techniques are reviewed,including the im...Recent developments in spectral white-light interferometry(WLI)are reviewed.Firstly,the techniques for obtaining optical spectrum are introduced.Secondly,some novel measurement techniques are reviewed,including the improved peak-to-peak WLI,improved wavelength-tracking WLI,Fourier transform WLI,and 3×3 coupler based WLI.Furthermore,a hybrid measurement for the intensity-type sensors,interferometric sensors,and fiber Bragg grating sensors is achieved.It is shown that these developments have assisted in the progress of WLI.展开更多
In this paper,we present a suppression method for the thermal drift of an ultra-stable laser interferometer.The detailed analysis on the Michelson interferometer indicates that the change in optical path length induce...In this paper,we present a suppression method for the thermal drift of an ultra-stable laser interferometer.The detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temperature variation can be effectively reduced by choosing proper thickness and/or incident angle of a compensator.Taking the optical bench of the Laser Interferometer Space Antenna Pathfinder as an example,we analyze the optical bench model with a compensator and show that the temperature coefficient of this laser interferometer can be reduced down to 1 pm/K with an incident angle of 0.267828 rad.The method presented in this paper can be used in the design of ultra-stable laser interferometers,especially for space-based gravitational waves detection.展开更多
基金Projected supported by the Innovation Research Foundations for Postgraduates of National University of Defense Technology and Hunan Provincethe National Natural Science Foundation of China (Grant No. 61008037)
文摘The nano-particle-based planar laser scattering （NPLS） technique is used to measure the density distribution in the supersonic mixing layer of the convective Mach number 0.12, and the optical path difference （OPL）, which is quite crucial for the study of aero-optics, is obtained by post processing. Based on the high spatiotemporal resolutions of the NPLS, the structure of the OPL is ana]ysed using wavelet methods. The coherent structures of the OPL are extracted using three methods, including the methods of thresholding the coefficients of the orthogonal wavelet transform and the wavelet packet transform, and preserving a number of wavelet packet coefficients with the largest amplitudes determined by the entropy dimension. Their performances are compared, and the method using the wavelet packet is the best. Based on the viewpoint of multifractals, we study the OPL by the wavelet transform maxima method （WTMM）, and the result indicates that its scaling behaviour is evident.
基金supported by the State Key Program of National Natural Science Foundation of China (Grant No. 40537031)the National Natural Science Foundation of China (Grant No. 40875013)+1 种基金the National Defense Basic Scientific Research Project, China (Grant No. A1420080187)the National High Technology Research and Development Program of China (Grant No. 2006AA12Z152)
文摘A simple method is applied to calculating the optical path difference （OPD） of a plane parallel uniaxial plate with an arbitrary optical axis direction. Then, the theoretical expressions of the OPD and lateral displacement （LD） of Savart polariscope under non-ideal conditions are obtained exactly. The variations of OPD and LD are simulated, and some important conclusions are obtained when the optical axis directions have an identical tolerance of ／pm 1^{{／circ}}. An application example is given that the tolerances of optical axis directions are gained according to the spectral resolution tolerances of the stationary polarization interference imaging spectrometer （SPIIS）. Several approximate formulae are obtained for explaining some conclusions above. The work provides a theoretical guidance for the optic design, crystal processing, installation and debugging, data analysis and spectral reconstruction of the SPIIS.
基金Supported by the National Basic Research Program of China under Grant No 2014CB340102
文摘To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974215)the Science Foundation of State Key Laboratory of Precision Spectroscopy,East China Normal University
文摘A fold optical path is utilized to capture and launch atoms in the atomic fountain. This improved technique reduces the laser power needed by 60 percent, facilitates suppression of the laser power fluctuations, and leads to a more simple and stable system.
基金Project supported by the National Natural Science Foundation of China(Grant No.61008037)the National Basic Research Program of China(Grant No.2009CB724100)
文摘Based on the measurement of one-dimensional （1D） optical path difference （OPD） of the supersonic turbulent bound- ary layer, an analytical form for the power spectrum of the two-dimensional （2D） OPD is obtained with its structure function and under the locally homogeneous isotropic assumption. The universality of this spectrum is argued, and its validity is checked by the comparison with experimental result. The potential applications of this model in theoretical and numerical studies are emphasized. Another contribution of this work is around the application of correlation function to analyzing the statistics of OPD. Based on our results and other results published elsewhere, we show that the OPD is often not stationary, and one should be cautious about using this tool.
基金was supported by the ICT R&D programs of Ministry of Science, ICT and Future Planning/Institute for Information & Communications Technology Promotion (Grant No. B0101-16-1355)the Korea Institute of Science and Technology research program (Grant No. 2E27231)Korea Institute of Science and Technology-Electronics And Telecommunications Research Institute research program (Grant No. 2V05340)
文摘We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.
基金Project supported by the National Natural Science Foundation of China (Grant No. 41005019)the Fund from the Chinese Academy of Scieneces for West Yong Scientists (Grant No. XAB 2016A07)the Natural Science Basic Research Program of Shaanxi Province, China (Grant No. 2019JQ-931).
文摘Instrument drifts introduce additional phase errors into atmospheric wind measurement of Doppler asymmetric spatial heterodyne spectroscopy (DASH). Aiming at the phase sensitivity of DASH to instrument drifts, in this paper we calculate the optical path difference (OPD) and present an accurate formula of DASH interferogram. By controlling variables in computational ray-tracing simulations and laboratory experiments, it is indicated that initial phase is directly determined by incident wavenumber, OPD offset and field of view (FOV). Accordingly, it is indicated that retrieved phase of DASH is sensitive to slight structural change caused by instrument drift, which provides the proof of necessary-to-track and -correct phase errors from instrument drifts.
基金Project supported by the National High-Tech Research and Development Program of China(Grant No.2011AA050518)
文摘In this paper, the light trapping characteristics of glass substrate with hemisphere pit （HP） arrays in thin film Si solar cells are theoretically studied via a numerical approach. It is found that the HP glass substrate has good antireflection properties. Its surface reflectance can be reduced by - 50% compared with planar glass. The HP arrays can make the unabsorbed light return to the absorbing layer of solar cells, and the ratio of second absorption approximately equals 30%. Thus, the glass substrate with the hemisphere pit arrays （HP glass） can effectively reduce the total reflectivity of a solar celt from 20% to 13%. The lip glass can also prolong the optical path length. The numerical results show that the total optical path length of the thin film Si solar cell covered with the HP glass increases from 2ω to 409. These results are basically consistent with the experimental results.
基金Project supported by the National Natural Science Foundation of China (Grant No.40875013)the National Defense Basic Scientific Research Project (Grant No.A1420080187)+1 种基金the National High Technology Research and Development Program of China (Grant No.2006AA12Z152)the State Key Program of National Natural Science Foundation of China (Grant No.40537031)
文摘A static polarization interferometer for measuring upper atmospheric winds is presented, based on two Savart plates with their optical axes perpendicular to each other. The principle and characteristics of the interferometer are described. The interferometer with a wide field of view can offer a stable benchmark optical path difference over a specified spectral region of 0.55-0.63μm because there are no quarter wave plates. Since the instrument employs a straight line common-path configuration but without moving parts and slits, it is very compact, simple, inherently robust and has high throughput. The paper is limited to a theoretical analysis.
基金the Ministerial Level Foundation (4645103030401)
文摘Design method and procedures of computer-generated hologram （CGH） used for aspheric test are in- troduced in detail. For CGH phase calculation, virtual medium which has zero refractive index at given wavelength is used to model ideal aspheric wavefront. Reflective Fresnel zones located in a ring area concentric to the CGH structure is designed to reduce or eliminate alignment errors. Substrate figure error, pattern distortion, etching and duty cycle variations that influence the reconstructed wavefront are quantitatively analyzed in theory and corresponding error equations are obtained to guide the tolerance distribution during CGH fabricating. A design example is given and the uncertainty of t achieves λ20.
基金Project supported by the Innovation Foundation for Postgraduates in the National University of Defense Technology,China(Grant No. S090701)
文摘A seed laser oscillating at different frequencies is proved to have the potential to mitigate the stimulated Brillouin scattering（SBS） effect in a fiber amplifier,which may increase the emission power of a coherent beam combination（CBC） system greatly.In this study,a basic mathematical model describing the multi-wavelength CBC is proposed on the fundamentals of CBC.A useful method for estimating the combination effect and analysing the feasibility and the validity of the multi-wavelength coherent combination is provided.In the numerical analysis,accordant results with four-wavelength four-channel CBC experiments are obtained.Through calculations of some examples with certain spectra,the unanticipated excellent combination effect with a few frequencies involved is explained,and the dependence of the combination effect on the variance of the amplifier chain length and the channel number is clarified.
文摘Abstract: In order to solve the problem of high precision, complete electric insulating detection of the pressure measuring system, we have developed the three - beam interferometer. In this paper, the operation principle, structure of the system and measuring results are given.
文摘In strip surface quality inspection systems based on the machine vision detection technology ,image quality is a key factor affecting the final detection performance. Composite imaging methods, such as bright and dark field imaging or reflection and transmission imaging, can reveal more information by emphasizing different image aspects. Defect detection rates and defect recognition accuracy can be improved by integrating and matching information from different image acquisition settings. Practical application shows that transmission and reflection composite imaging can improve the imaging quality of penetrative defects, while bright and dark field composite imaging can enhance imaging of defects such as color deviation and stains.
文摘In this study,we present a dual-Fizeau-interferometer-based high-speed and wide-range fiber-optic Fabry-Perot(F-P)demodulation system.We employ two Fizeau interferometers with air cavity thickness satisfying the quadrature requirement to increase the demodulation speed and broaden the demodulation range in order to address the issues of the existing fiber F-P demodulation system's sluggish demodulation rate and limited range.In order to investigate the demodulation properties of the dual-Fizeau-interferometer-based demodulation system,we derive and create a theoretical model of the system.The theoretical model,which primarily consists of the structural design of the interferometer and the study of the center wavelength of the light sources and their bandwidth selection,is used to construct the optical structure of the demodulation system.According to the calculation results,the demodulated signal exhibits the best contrast ratio when the two light sources'respective center wavelengths are 780nm and 850nm,and their bandwidths are 28nm and 30 nm.Finally,we finish evaluating the demodulation system's demodulation performance,parameter calibration,and assembly debugging.The test results demonstrate the constant operation of the demodulation system,an update rate of 100kHz,a demodulation range of 4.74μm,and a cavity length resolution of approximately 5 nm.Additionally,the system can perform high speed demodulation thanks to the light emitting diode's(LED's)nanosecond level switching speed and the usage of a single point detector.
文摘Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwave photonics filtering[1–3],arbitrary generation[4–6]and analog to digital conversion[7]。
基金supported by the National Natural Science Foundation of China(Nos.62275065,62022032,and 61875047)Natural Science Foundation of Heilongjiang Province of China(No.YQ2019F006)。
文摘In the field of absorption spectroscopy,the multipass cell[MPC]is one of the key elements.It has the advantages of simple structure,easy adjustment,and high spectral coverage,which is an effective way to improve the detection sensitivity of gas sensing systems such as tunable diode laser absorption spectroscopy.This invited paper summarizes the design theory and the research results of some mainstream types of MPCs based on two mirrors and more than two mirrors in recent years,and briefly introduces the application of some processed products.The design theory of modified ABCD matrix and vector reflection principle are explained in detail.Finally,trends in its development are predicted.
基金This work was supported by the National Natural Scientific Foundation of China(51075037)the Program for New Century Excellent Talents(NCET)at the University of China and Chinese 863 Project(2008AA04Z406).
文摘Recent developments in spectral white-light interferometry(WLI)are reviewed.Firstly,the techniques for obtaining optical spectrum are introduced.Secondly,some novel measurement techniques are reviewed,including the improved peak-to-peak WLI,improved wavelength-tracking WLI,Fourier transform WLI,and 3×3 coupler based WLI.Furthermore,a hybrid measurement for the intensity-type sensors,interferometric sensors,and fiber Bragg grating sensors is achieved.It is shown that these developments have assisted in the progress of WLI.
基金supported by the Natural Science Foundation of Guangdong Province (No. 2021A1515010198)the Guangzhou Science and Technology Plan Project (No. 202102020794)the National Key R&D Program of China (No. 2020YFC2200500)
文摘In this paper,we present a suppression method for the thermal drift of an ultra-stable laser interferometer.The detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temperature variation can be effectively reduced by choosing proper thickness and/or incident angle of a compensator.Taking the optical bench of the Laser Interferometer Space Antenna Pathfinder as an example,we analyze the optical bench model with a compensator and show that the temperature coefficient of this laser interferometer can be reduced down to 1 pm/K with an incident angle of 0.267828 rad.The method presented in this paper can be used in the design of ultra-stable laser interferometers,especially for space-based gravitational waves detection.
