Patent ID: 6996309

Claim:
An optical signal processor for processing light fed to an input port according to a wavelength thereof and then outputting the processed light from an output port; the optical signal processor comprising: a wavelength demultiplexer for spatially demultiplexing the inputted light in terms of wavelengths and outputting demultiplexed wavelength light components into respective optical paths different from each other; a first light-converging optical system for converging the wavelength light components outputted from the wavelength demultiplexer; a first reflecting mirror having a reflecting surface at a position where the light components are converged by the first light-converging optical system and causing the reflecting surface to reflect the wavelength light components converged by the first light-converging optical system such that the reflected light components are fed into the first light-converging optical system; and optical path turning means for inputting light arriving by way of the wavelength demultiplexer, first light-converging optical system, first reflecting mirror, first light-converging optical system, and wavelength demultiplexer in succession after being fed into the input port, and turning an optical path of the light such that the light travels the wavelength demultiplexer, first light-converging optical system, first reflecting mirror, first light-converging optical system, and wavelength demultiplexer in succession so as to be outputted from the output port; wherein the optical path turning means inverts an image of each wavelength light component reflected by the first reflecting mirror between an incoming optical path from the input port to the optical path turning means and an outgoing optical path from the optical path turning means to the output port.