A multifunctional optical diagnostic system,which includes an interferometer,a refractometer and a multi-frame shadowgraph,has been developed at the Shenguang-II upgrade laser facility to characterize underdense plasm...A multifunctional optical diagnostic system,which includes an interferometer,a refractometer and a multi-frame shadowgraph,has been developed at the Shenguang-II upgrade laser facility to characterize underdense plasmas in experiments of the double-cone ignition scheme of inertial confinement fusion.The system employs a 266 nm laser as the probe to minimize the refraction effect and allows for flexible switching among three modes of the interferometer,refractometer and multi-frame shadowgraph.The multifunctional module comprises a pair of beam splitters that attenuate the laser,shield stray light and configure the multi-frame and interferometric modules.By adjusting the distance and angle between the beam splitters,the system can be easily adjusted and switched between the modes.Diagnostic results demonstrate that the interferometer can reconstruct electron density below 10^(19)cm^(–3),while the refractometer can diagnose density approximately up to 10^(20)cm^(–3).The multi-frame shadowgraph is used to qualitatively characterize the temporal evolution of plasmas in the cases in which the interferometer and refractometer become ineffective.展开更多
An optical fiber extrinsic Fabry-Perot interferometer （EFPI） is designed and fabricated for refractive index （RI） sensing. To test the RI of liquid, the following two different methods are adopted： the wavelength...An optical fiber extrinsic Fabry-Perot interferometer （EFPI） is designed and fabricated for refractive index （RI） sensing. To test the RI of liquid, the following two different methods are adopted： the wavelength tracking method and the Fourier-transform white-light interferometry （FTWLI）. The sensitivities of sensors with cavity lengths of 288.1 and 358.5 μm are 702.312 nm/RIU and 396.362 μm/RIU, respectively, by the two methods. Our work provides a new kind of RI sensor with the advantages of high sensitivity, mechanical robustness, and low cross sensitivity to temperature. Also, we provide a new method to deal with gold film with a femtosecond laser.展开更多
An interesting reflection phenomenon in a dual metal grating （DMG） structure is studied, which is related to the competition between Fabry-Prot （F-P） resonance effect and evanescent-field coupling effect inside th...An interesting reflection phenomenon in a dual metal grating （DMG） structure is studied, which is related to the competition between Fabry-Prot （F-P） resonance effect and evanescent-field coupling effect inside the gap between the two composing single metal gratings. This competition leads to high angular sensitivity in response to the refractive index variation of the sample solution in the gap. A reflex optical sensor with high sensitivity based on DMG for detecting the change in refractive index is proposed and its performance theoretically is discussed.展开更多
Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition （MCVD） followed by the solution-doping method. Ultraviolet （UV） optical absorption, photoluminescence （PL） spectra...Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition （MCVD） followed by the solution-doping method. Ultraviolet （UV） optical absorption, photoluminescence （PL） spectra under 978-nm laser diode （LD） pumping, and refractive index change after exposure to 266-nm laser pulses are obtained. There is only a little change in the PL spectra while a positive refractive index change up to 2×10^-4 is observed after 30-min exposure to 266-nm laser pulses. The results show that both of the peculiar photosensitivity of Smdoped silica and the gain property of Yb-doped silica fiber are preserved in the Sn/Yb codoped silica optical fiber preform. The experimental data suggest that the photosensitivity of the fiber preform under high energy density laser irradiation should be mainly due to the bond-breaking of oxygen deficient defects, while under relatively low energy density laser irradiation, the refractive index change probably originates from the photoconversion of optically active defects.展开更多
The surfaces and refractive index of crystalline lens play an important role in the optical performance of human eye. On the basis of two eye models, which are widely applied at present, the effect of lens surfaces an...The surfaces and refractive index of crystalline lens play an important role in the optical performance of human eye. On the basis of two eye models, which are widely applied at present, the effect of lens surfaces and its refractive index distribution on optical imaging is analyzed with the optical design software ZEMAX （Zemax Development Co., San Diego, USA）. The result shows that good image quality can be provided by the aspheric lens surfaces or （and） the gradient-index （GRIN） distribution. It has great potential in the design of intraocular lens （IOL）. The eye models with an intraocular implantation are presented.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA25010200)the National Key R&D Program of China(No.2023YFA160005602)the National Natural Science Foundation of China(No.12375242)
文摘A multifunctional optical diagnostic system,which includes an interferometer,a refractometer and a multi-frame shadowgraph,has been developed at the Shenguang-II upgrade laser facility to characterize underdense plasmas in experiments of the double-cone ignition scheme of inertial confinement fusion.The system employs a 266 nm laser as the probe to minimize the refraction effect and allows for flexible switching among three modes of the interferometer,refractometer and multi-frame shadowgraph.The multifunctional module comprises a pair of beam splitters that attenuate the laser,shield stray light and configure the multi-frame and interferometric modules.By adjusting the distance and angle between the beam splitters,the system can be easily adjusted and switched between the modes.Diagnostic results demonstrate that the interferometer can reconstruct electron density below 10^(19)cm^(–3),while the refractometer can diagnose density approximately up to 10^(20)cm^(–3).The multi-frame shadowgraph is used to qualitatively characterize the temporal evolution of plasmas in the cases in which the interferometer and refractometer become ineffective.
基金supported by the National Basic Research Program of China (No.2011CB013000)the 863 Program of the Ministry of Science and Technology of China (No.2015AA043504)the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China (No.708018)
文摘An optical fiber extrinsic Fabry-Perot interferometer （EFPI） is designed and fabricated for refractive index （RI） sensing. To test the RI of liquid, the following two different methods are adopted： the wavelength tracking method and the Fourier-transform white-light interferometry （FTWLI）. The sensitivities of sensors with cavity lengths of 288.1 and 358.5 μm are 702.312 nm/RIU and 396.362 μm/RIU, respectively, by the two methods. Our work provides a new kind of RI sensor with the advantages of high sensitivity, mechanical robustness, and low cross sensitivity to temperature. Also, we provide a new method to deal with gold film with a femtosecond laser.
基金supported by the National Natural Science Foundation of China (Nos. 10974102, 10874078,11074116, and 10934003)the National Basic Research Program of China (No. 2006CB921805)the Open Project of the State Key Laboratory of Functional Materials for Informatics
文摘An interesting reflection phenomenon in a dual metal grating （DMG） structure is studied, which is related to the competition between Fabry-Prot （F-P） resonance effect and evanescent-field coupling effect inside the gap between the two composing single metal gratings. This competition leads to high angular sensitivity in response to the refractive index variation of the sample solution in the gap. A reflex optical sensor with high sensitivity based on DMG for detecting the change in refractive index is proposed and its performance theoretically is discussed.
基金supported by the National Natural Science Foundation of China (Nos. 10074011 and 60378034)the Ministry of Science and Technology of China (Nos. 02JD14001 and 03DJ14001).
文摘Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition （MCVD） followed by the solution-doping method. Ultraviolet （UV） optical absorption, photoluminescence （PL） spectra under 978-nm laser diode （LD） pumping, and refractive index change after exposure to 266-nm laser pulses are obtained. There is only a little change in the PL spectra while a positive refractive index change up to 2×10^-4 is observed after 30-min exposure to 266-nm laser pulses. The results show that both of the peculiar photosensitivity of Smdoped silica and the gain property of Yb-doped silica fiber are preserved in the Sn/Yb codoped silica optical fiber preform. The experimental data suggest that the photosensitivity of the fiber preform under high energy density laser irradiation should be mainly due to the bond-breaking of oxygen deficient defects, while under relatively low energy density laser irradiation, the refractive index change probably originates from the photoconversion of optically active defects.
基金the National Na-ture Science Foundation of China (No.60678048)the Nature Science Foundations of Jiangsu Province (No.BK2007207 and BS2007061).
文摘The surfaces and refractive index of crystalline lens play an important role in the optical performance of human eye. On the basis of two eye models, which are widely applied at present, the effect of lens surfaces and its refractive index distribution on optical imaging is analyzed with the optical design software ZEMAX （Zemax Development Co., San Diego, USA）. The result shows that good image quality can be provided by the aspheric lens surfaces or （and） the gradient-index （GRIN） distribution. It has great potential in the design of intraocular lens （IOL）. The eye models with an intraocular implantation are presented.
