OPTICAL COUPLING UNIT AND FIBER PHOTOELECTRIC SENSOR USING IT

摘要

PURPOSE:To improve light transmitting efficiency between an LED and an optical fiber. CONSTITUTION:A total reflection unit 13 which totally reflects emitted light from the LED 10 and makes it incident on the optical fibers 14 is constituted to be tapered and in a state where incident angle of the incident light on the optical fiber 14 is made smaller than the incident angle decided by the NA (numerical aperture) of the optical fiber 14. A parabollic reflection unit 15 which reflects divergent light from the LED 10 and makes it incident directly on the optical fiber 14 at the incident angle smaller than the incident angle decided by the NA(numerical aperture) of the optical fiber 14 is made in contact with the outside of the neighboring area of the LED bonding part of the unit 13.