Patent ID: 8369666

Claim:
An optical wavelength multiplexing/de-multiplexing circuit which is configured with an arrayed waveguide grating and a Mach-Zehnder interferometer circuit, said arrayed waveguide grating comprising: an arrayed waveguide including a waveguide having a length sequentially increased by a certain optical path length difference; first and second slab waveguides connected to both end parts of said arrayed waveguide, respectively; and temperature compensation means for compensating a main temperature dependence at a transmission wavelength, and said Mach-Zehnder interferometer circuit comprising: first and second arm waveguides having a certain optical path length difference therebetween; a latter stage optical coupler connected between one end in each of said first and second arm waveguides and an end part of said first slab waveguide; a former stage optical coupler connected to the other end in each of said first and second arm waveguides; and temperature compensation means for compensating a main temperature dependence at a transmission wavelength, wherein said former stage optical coupler is a phase difference generation coupler configured with: a first optical coupler causing light to branch in a specific intensity ratio; a third arm waveguide and a fourth arm waveguide further connected to said first optical coupler and having a certain optical path length difference therebetween; and a second coupler further connected to each of said third and fourth arm waveguides, the former stage optical coupler including a mechanism which changes the optical path length difference between said third arm waveguide and said fourth arm waveguide by temperature and is configured so as to cause a temperature dependence of the transmission wavelength in said Mach-Zehnder interferometer circuit, the temperature dependence being modulated by a temperature-induced change of a phase difference between two outputs of said phase difference generation coupler, to compensate a remaining temperature dependence of the transmission wavelength in said arrayed waveguide grating.