Using lock-in amplifer and proportional, integral, and derivative (PID) electric circuit, the frequency of diode laser is stabilized on a highly mechanical stable Fabry-Perot (FP) cavity transmission peak. When the fr...Using lock-in amplifer and proportional, integral, and derivative (PID) electric circuit, the frequency of diode laser is stabilized on a highly mechanical stable Fabry-Perot (FP) cavity transmission peak. When the frequency locking system is on, the frequency tunable range of the laser is about 4 GHz around the D1 transition of Rb. The laser frequency tuning is implemented by scanning the FP cavity length. The fluctuation of frequency of the output laser is less than 1 MHz, and the drift of the center frequency is less than 1.5 MHz in 1.5 min. This system has great potential of the application in the experimental investigation of the interaction between light and atoms, especially, for the case of far off the atomic resonance.展开更多
The characteristics of coherent coupling in Mach-Zehnder erbium-doped fiber laser cavity are experimentally studied. By virtue of a seemly controlling of length difference between two interferometric arms, the obtaine...The characteristics of coherent coupling in Mach-Zehnder erbium-doped fiber laser cavity are experimentally studied. By virtue of a seemly controlling of length difference between two interferometric arms, the obtained comb-like spectrum of interferometer resonator with a period of 0.06 nm commendably agrees with the theory of self-organization coherence. The coherent output exits from the output mirror of a fiber Bragg grating with 4.5% reflectivity. A high coherent combining efficiency of 94% is obtained. Investigation on characteristics of the leak power opens out self-organization mechanism in Mach-Zehnder composite cavity.展开更多
To determine the amplitude of weak sinusoidal water surface acoustic wave （WSAW）, a method based on the spectrum analysis of the phase-modulated interference signal is developed. Calculated from the amplitude spec- ...To determine the amplitude of weak sinusoidal water surface acoustic wave （WSAW）, a method based on the spectrum analysis of the phase-modulated interference signal is developed. Calculated from the amplitude spec- trum of the detection signal, a characteristic ratio indicates that the phase-modulation depth of a WSAW is suggested by determining the amplitude of a WSAW according to their functional relationship. Experimental investigations for a 4 kHz WSAW evaluate the measurement＇s precision with an amplitude measurement stan- dard deviation of 0.12 nm. The measurement accuracy also is demonstrated by the experimental investigations. The theory of this method is briefly described, and the experimental setup is presented.展开更多
We report a high-resolution rapid thermal sensing based on adaptive dual comb spectroscopy interrogated with a phase-shifted fiber Bragg grating(PFBG). In comparison with traditional dual-comb systems, adaptive dual-c...We report a high-resolution rapid thermal sensing based on adaptive dual comb spectroscopy interrogated with a phase-shifted fiber Bragg grating(PFBG). In comparison with traditional dual-comb systems, adaptive dual-comb spectroscopy is extremely simplified by removing the requirement of strict phase-locking feedback loops from the dual-comb configuration. Instead, two free-running fiber lasers are adopted as the light sources. Because of good compensation of fast instabilities with adaptive techniques, the optical response of the PFBG is precisely characterized through a fast Fourier transform of the interferograms in the time domain. Single-shot acquisition can be accomplished rapidly within tens of milliseconds at a spectral resolution of 0.1 pm, corresponding to a thermal measurement resolution of 0.01 ℃. The optical spectral bandwidth of the measurement also exceeds 14 nm, which indicates a large dynamic temperature range. It shows great potential for thermal sensing in practical outdoor applications with a loose self-control scheme in the adaptive dual-comb system.展开更多
A novel optical excitation and detection apparatus was used to investigate the characteristics of silicon micro-resonators, which was activated into vibration by a laser beam irradiation. The beam diameter of the exci...A novel optical excitation and detection apparatus was used to investigate the characteristics of silicon micro-resonators, which was activated into vibration by a laser beam irradiation. The beam diameter of the excitation light was less than 10 μm. The vibration amplitude of the resonator was detected by the interferometer with high resolution of 0.1 nm and measurement repeatability of less than 3 nm. The resonant frequency of the micro-resonator was obtained to be 8.75 kHz with full-width at half-maximum （FWHM） of 0.18 kHz. It is shown that the method is useful and reliable for measuring micro-displacement and micro-vibration of minute objects with nanometer accuracy.展开更多
A polarization Fizeau interferometer based on birefringent thin film is presented.The interferometer adopts a birefringent thin film to obtain orthogonally polarized and strictly common-path reference and test beams.A...A polarization Fizeau interferometer based on birefringent thin film is presented.The interferometer adopts a birefringent thin film to obtain orthogonally polarized and strictly common-path reference and test beams.Advantages include ease of implementation on large-aperture interferometer,measuring test optics from long distance,and achieving high fringe visibility.The phase shift is obtained by combining a quarterwave plate and an analyzer.The concepts illustrated are verified experimentally.展开更多
The single-sided and dual-sided high reflective mirrors were deposited with ion-beam sputtering （IBS）. When the incident light entered with 45°, the reflectance of p-polarized light at 1064 nm exceeded 99.5%. S...The single-sided and dual-sided high reflective mirrors were deposited with ion-beam sputtering （IBS）. When the incident light entered with 45°, the reflectance of p-polarized light at 1064 nm exceeded 99.5%. Spectrum was gained by spectrometer and weak absorption of coatings was measured by surface thermal lensing （STL） technique. Laser-induced damage threshold （LIDT） was determined and the damage morphology was observed with Lecia-DMRXE microscope simultaneously. The profile of coatings was measured with Mark III-GPI digital interferometer. It was found that the reflectivity of mirror exceeded 99.9% and its absorption was as low as 14 ppm. The reflective bandwidth of the dual-sided sample was about 43 nm wider than that of single-sided sample, and its LIDT was as high as 28 J/cm^2, which was 5 J/cm^2 higher than that of single-sided sample. Moreover, the profile of dual-sided sample was better than that of substrate without coatings.展开更多
文摘Using lock-in amplifer and proportional, integral, and derivative (PID) electric circuit, the frequency of diode laser is stabilized on a highly mechanical stable Fabry-Perot (FP) cavity transmission peak. When the frequency locking system is on, the frequency tunable range of the laser is about 4 GHz around the D1 transition of Rb. The laser frequency tuning is implemented by scanning the FP cavity length. The fluctuation of frequency of the output laser is less than 1 MHz, and the drift of the center frequency is less than 1.5 MHz in 1.5 min. This system has great potential of the application in the experimental investigation of the interaction between light and atoms, especially, for the case of far off the atomic resonance.
基金the National Key Basic Research and Development Programme of China(No.2003CB314906)the Project of the Key Laboratory Foundation of Solid Laser Technology (No.51438020205JW1502)the Tianjin Natural Science Foundation(No. 6YFJZJC00300).
文摘The characteristics of coherent coupling in Mach-Zehnder erbium-doped fiber laser cavity are experimentally studied. By virtue of a seemly controlling of length difference between two interferometric arms, the obtained comb-like spectrum of interferometer resonator with a period of 0.06 nm commendably agrees with the theory of self-organization coherence. The coherent output exits from the output mirror of a fiber Bragg grating with 4.5% reflectivity. A high coherent combining efficiency of 94% is obtained. Investigation on characteristics of the leak power opens out self-organization mechanism in Mach-Zehnder composite cavity.
基金supported by the National Natural Science Foundation of China under Grant No.61108073
文摘To determine the amplitude of weak sinusoidal water surface acoustic wave （WSAW）, a method based on the spectrum analysis of the phase-modulated interference signal is developed. Calculated from the amplitude spec- trum of the detection signal, a characteristic ratio indicates that the phase-modulation depth of a WSAW is suggested by determining the amplitude of a WSAW according to their functional relationship. Experimental investigations for a 4 kHz WSAW evaluate the measurement＇s precision with an amplitude measurement stan- dard deviation of 0.12 nm. The measurement accuracy also is demonstrated by the experimental investigations. The theory of this method is briefly described, and the experimental setup is presented.
基金the National Instrumentation Program (No. 2012YQ150092)the China Postdoctoral Science Foundation (No. 2015M581634)+1 种基金the National Natural Science Foundation of China (No. 11704253)the Shanghai Youth Science and Technology Talent Sailing Program (No. 17YF1413100).
文摘We report a high-resolution rapid thermal sensing based on adaptive dual comb spectroscopy interrogated with a phase-shifted fiber Bragg grating(PFBG). In comparison with traditional dual-comb systems, adaptive dual-comb spectroscopy is extremely simplified by removing the requirement of strict phase-locking feedback loops from the dual-comb configuration. Instead, two free-running fiber lasers are adopted as the light sources. Because of good compensation of fast instabilities with adaptive techniques, the optical response of the PFBG is precisely characterized through a fast Fourier transform of the interferograms in the time domain. Single-shot acquisition can be accomplished rapidly within tens of milliseconds at a spectral resolution of 0.1 pm, corresponding to a thermal measurement resolution of 0.01 ℃. The optical spectral bandwidth of the measurement also exceeds 14 nm, which indicates a large dynamic temperature range. It shows great potential for thermal sensing in practical outdoor applications with a loose self-control scheme in the adaptive dual-comb system.
基金This work was supported by the National Natural Science Pundation under Grant No. 60578051.
文摘A novel optical excitation and detection apparatus was used to investigate the characteristics of silicon micro-resonators, which was activated into vibration by a laser beam irradiation. The beam diameter of the excitation light was less than 10 μm. The vibration amplitude of the resonator was detected by the interferometer with high resolution of 0.1 nm and measurement repeatability of less than 3 nm. The resonant frequency of the micro-resonator was obtained to be 8.75 kHz with full-width at half-maximum （FWHM） of 0.18 kHz. It is shown that the method is useful and reliable for measuring micro-displacement and micro-vibration of minute objects with nanometer accuracy.
基金supportedby the National Natural Science Foundation of China(No. 60808018)the State Key Laboratory of Applied Optics, China (No. Y1Q03FQK06)
文摘A polarization Fizeau interferometer based on birefringent thin film is presented.The interferometer adopts a birefringent thin film to obtain orthogonally polarized and strictly common-path reference and test beams.Advantages include ease of implementation on large-aperture interferometer,measuring test optics from long distance,and achieving high fringe visibility.The phase shift is obtained by combining a quarterwave plate and an analyzer.The concepts illustrated are verified experimentally.
文摘The single-sided and dual-sided high reflective mirrors were deposited with ion-beam sputtering （IBS）. When the incident light entered with 45°, the reflectance of p-polarized light at 1064 nm exceeded 99.5%. Spectrum was gained by spectrometer and weak absorption of coatings was measured by surface thermal lensing （STL） technique. Laser-induced damage threshold （LIDT） was determined and the damage morphology was observed with Lecia-DMRXE microscope simultaneously. The profile of coatings was measured with Mark III-GPI digital interferometer. It was found that the reflectivity of mirror exceeded 99.9% and its absorption was as low as 14 ppm. The reflective bandwidth of the dual-sided sample was about 43 nm wider than that of single-sided sample, and its LIDT was as high as 28 J/cm^2, which was 5 J/cm^2 higher than that of single-sided sample. Moreover, the profile of dual-sided sample was better than that of substrate without coatings.
