The golden films with various subwavelength hole arrays on the film surface are designed and fabricated on glass substrate by electron beam lithograply(EBL),focused ion beam(FIB),and reactive ion etching(RIE),respecti...The golden films with various subwavelength hole arrays on the film surface are designed and fabricated on glass substrate by electron beam lithograply(EBL),focused ion beam(FIB),and reactive ion etching(RIE),respectively.The influences of the hole array symmetry and the hole shape on the light-enhanced transmission through the films are observed and simulated.The experimental results show that when the array lattice constant and the hole diameter are the same in the different array structures which are 1 μm and 350 nm respectively,the square hole arrays exhibit two transmission peaks at 1170 nm and 1580 nm with the transmissivities of 3% and 6%,respectively,while the hexagonal hole arrays exhibit an enhanced peak of 14% at 1340 nm;when the lattice constant and the duty cycle are the same for different array stucture,the transmission peaks are different for different hole shapes,which are at 763 nm with transmissivity of 12% for rectangular holes and at 703 nm with the one of 9%,respectively.The numerical simulation results by using the transfer matrix method(TMM) are consistent with the observed results.展开更多
The design of an ultra-compact SOI-based 1×2 3 dB multimode interference(MMI) coupler is proposed.The symmetric multimode interference structure and deeply-etched parabolically tapered multimode waveguide are use...The design of an ultra-compact SOI-based 1×2 3 dB multimode interference(MMI) coupler is proposed.The symmetric multimode interference structure and deeply-etched parabolically tapered multimode waveguide are used in the device.The length of the device is reduced by about 87% compared with general multimode interference straight couplers.Based on effective index method(EIM) and two dimensional beam propagation method(2D-BPM),the structure parameters are optimized and the fabrication tolerances are analyzed.The results indicate that the performance of the coupler is deeply affected by the coupler's width,etching depth and photolithography alignment error in perpendicular direction.展开更多
Conventionally, the polarization of a synchrotron soft X-ray beam is measured through a polarimeter based on multilayer optical elements. The major drawback of the traditional approach is the difficulty in comparing d...Conventionally, the polarization of a synchrotron soft X-ray beam is measured through a polarimeter based on multilayer optical elements. The major drawback of the traditional approach is the difficulty in comparing different configurations due to the misalignment of each incident angle. In this paper, a new analytical model, based on the variation of reflectivity for different incident angles, is established to facilitate the extraction of important polarization-related information, i.e. angular distribution of polarization components, a tiny change of the direction of azimuth rotation axis of polarizer, etc.展开更多
文摘The golden films with various subwavelength hole arrays on the film surface are designed and fabricated on glass substrate by electron beam lithograply(EBL),focused ion beam(FIB),and reactive ion etching(RIE),respectively.The influences of the hole array symmetry and the hole shape on the light-enhanced transmission through the films are observed and simulated.The experimental results show that when the array lattice constant and the hole diameter are the same in the different array structures which are 1 μm and 350 nm respectively,the square hole arrays exhibit two transmission peaks at 1170 nm and 1580 nm with the transmissivities of 3% and 6%,respectively,while the hexagonal hole arrays exhibit an enhanced peak of 14% at 1340 nm;when the lattice constant and the duty cycle are the same for different array stucture,the transmission peaks are different for different hole shapes,which are at 763 nm with transmissivity of 12% for rectangular holes and at 703 nm with the one of 9%,respectively.The numerical simulation results by using the transfer matrix method(TMM) are consistent with the observed results.
文摘The design of an ultra-compact SOI-based 1×2 3 dB multimode interference(MMI) coupler is proposed.The symmetric multimode interference structure and deeply-etched parabolically tapered multimode waveguide are used in the device.The length of the device is reduced by about 87% compared with general multimode interference straight couplers.Based on effective index method(EIM) and two dimensional beam propagation method(2D-BPM),the structure parameters are optimized and the fabrication tolerances are analyzed.The results indicate that the performance of the coupler is deeply affected by the coupler's width,etching depth and photolithography alignment error in perpendicular direction.
基金Supported by National Natural Science Foundation of China (11075176)
文摘Conventionally, the polarization of a synchrotron soft X-ray beam is measured through a polarimeter based on multilayer optical elements. The major drawback of the traditional approach is the difficulty in comparing different configurations due to the misalignment of each incident angle. In this paper, a new analytical model, based on the variation of reflectivity for different incident angles, is established to facilitate the extraction of important polarization-related information, i.e. angular distribution of polarization components, a tiny change of the direction of azimuth rotation axis of polarizer, etc.
