Slim OFRS based on a grating input coupler and a microprism sensing surface

【摘要】 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.更多还原

【Abstract】 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.更多还原