Bidirectional optical module

A bidirectional optical module having a light-emitting device (1) for emitting transmitting signal light therefrom, an optical fiber (8) which the transmitting signal light emitted from the light-emitting device is made to enter, a light-receiving device (9) which receiving signal light made to emerge from the optical fiber is made to enter, and a wavelength splitting filter (4); the transmittingsignal light emitted from the light-emitting device being sent forward through the optical fiber, and the receiving signal light being received through the optical fiber. The bidirectional optical module has an optical device (optical isolator) consisting essentially of a reflection type polarizer (6) bonded to an end face of the optical fiber, a Faraday rotator (5) disposed integrally on the reflection type polarizer and an absorption type polarizer (3) disposed on an optical path extending between the light-emitting device and the wavelength splitting filter. The reflection type polarizer has a wavelength dependency