A slim optical fingerprint recognition sensor（OFRS） based on a grating input coupler and a microprism sensing surface is proposed.By using a subwavelength grating coupler,input light is coupled into the planar waveg...A slim optical fingerprint recognition sensor（OFRS） based on a grating input coupler and a microprism sensing surface is proposed.By using a subwavelength grating coupler,input light is coupled into the planar waveguide and the propagation angle is well engineered to avoid image overlap,thus an undistorted fingerprint is captured.For maintaining a thin structure,a microprism array is utilized to facilitate the breaking of total internal reflection under a large diffraction angle from the grating.The feasibility,efficiency,and image quality of the proposed structure are verified and discussed.The device has the advantages of a slim structure,a high image contrast,and a compact architecture,suitable for mobile devices.展开更多
基金supported by the National Natural Science Foundation of China under Nos.61370047,11374212,51235007,and 11421064
文摘A slim optical fingerprint recognition sensor（OFRS） based on a grating input coupler and a microprism sensing surface is proposed.By using a subwavelength grating coupler,input light is coupled into the planar waveguide and the propagation angle is well engineered to avoid image overlap,thus an undistorted fingerprint is captured.For maintaining a thin structure,a microprism array is utilized to facilitate the breaking of total internal reflection under a large diffraction angle from the grating.The feasibility,efficiency,and image quality of the proposed structure are verified and discussed.The device has the advantages of a slim structure,a high image contrast,and a compact architecture,suitable for mobile devices.
