Patent ID: 7907806
Filing Date: 2011-03-15
Classification: H04B

Abstract:
1. An optical mixer comprising: a first optical coupler that receives signal light, branches the signal light and outputs first and second signal light; a second optical coupler that receives local light, branches the local light and outputs first and second local light; a third optical coupler that couples the first signal light outputted from the first optical coupler with the first local light outputted from the second optical coupler and outputs the coupled light; and a fourth coupler that couples the second signal light outputted from the first optical coupler with the second local light outputted from the second optical coupler and outputs the coupled light, at least one of waveguide lengths of the first and second signal light and waveguide lengths of the first and second local light being longer or shorter than other waveguide lengths by π/2 and the waveguide from the first optical coupler to the fourth optical coupler intersecting the waveguide from the second optical coupler to the third optical coupler, wherein the waveguide from the first optical coupler to the third optical coupler and the waveguide from the second optical coupler to the fourth optical coupler are each provided with loss compensating means for compensating for loss that occurs when the waveguide from the first optical coupler to the fourth optical coupler intersects the waveguide from the second optical coupler to the third optical coupler.