Patent ID: 7146077
Filing Date: 2006-12-05
Classification: G02B,H01S

Abstract:
1. An optical coupler type filter comprising: a first waveguide, provided with first and second terminals, receiving light inputted from an external light source; a second waveguide provided with a third terminal; a coupling region, wherein the first and second waveguides are adjacent to each other so as to couple light between said first and second waveguides; and a grating, disposed in the coupling region, for outputting an extracted light, having a wavelength coinciding with a reflected wavelength, from the received light inputted from the first terminal, to the third terminal and outputting a residual transmitted light, from the received light inputted from the first terminal, to the second terminal, wherein the length of a sub-region of the coupling region formed between the grating and the first terminal is set to minimize the power of a recurrent light reflected by the grating, having a wavelength coinciding with the reflected wavelength from the received light inputted from the first terminal and outputted to the first terminal.