Optical reflector, optical system and optical multiplexer/demultiplexer device

An optical reflector, an optical multiplexer/demultiplexer device and an optical system which can allow more flexible arrangement of an optical filter thereof, and enhance performance of wavelength division multiplexing communication thereof are provided. An optical reflector according to the present invention comprises a first and second optical fiber 14, 16, each being connected to one side of an optical propagating region such as a rod lens 12 causing optical strength distributions depending on respective wavelengths of lights to be propagated in the optical propagating region; a mirror 18 disposed on the other side of the optical propagating region; and an optical filter 20 disposed between the first and second optical fibers 14, 16 and the mirror 18. The optical filter 20 is reflected a light having a first wavelength and allows another light having a second wavelength to be transmitted therethrough; and the mirror 18 is reflected the light having the second wavelength, so that the lights having the first and second wavelengths are propagated between the first optical fiber 14 and the second optical fiber 16.