Title :
Design of a Thin Film Photodetector with Angular Sensitivity for Optical Micro-Encoder
Author :
Choi, Bongseok ; Kanamori, Yoshiaki ; Hane, Kazuhiro
Author_Institution :
Tohoku Univ., Sendai
Abstract :
In this paper, we describe a directional thin film photodetector with the objective of optical micro-encoder application. A directional photodetector with a high absorption efficiency at a specific angle of incident light is based on guided-mode resonance (GMR) of subwavelength grating. The angular sensitivity of photodetector is designed to satisfy the condition that the diffracted light from the scale grating incidents at the angle of the resonance. A numerical calculation and actual device performance are presented.
Keywords :
encoding; micro-optics; optical sensors; photodetectors; thin film devices; angular sensitivity; diffracted light; directional thin film photodetector; guided-mode resonance; high absorption efficiency; optical micro-encoder; subwavelength grating; Diffraction gratings; Optical design; Optical distortion; Optical films; Optical filters; Optical interferometry; Optical sensors; Photodetectors; Resonance; Thin film sensors;
Conference_Titel :
Sensors, 2006. 5th IEEE Conference on
Conference_Location :
Daegu
Print_ISBN :
1-4244-0375-8
Electronic_ISBN :
1930-0395
DOI :
10.1109/ICSENS.2007.355774
