ASYMMETRICAL Y BRANCH WAVEGUIDE TYPE OPTICAL TAP

摘要

PURPOSE: To provide an optical tap which has a small loss and obtains a fixed branch ratio throughout a wide wavelength band and reduces the variance in branch ratio due to the waveguide production error by taking a linear waveguide, which branches in the same direction as the angle of expansion of a taper waveguide, as one branch waveguide and taking a bending waveguide like a curve as the other. ;CONSTITUTION: The optical tap consists of an input waveguide 11 having a core width W, a branch waveguide 13 which is linearly extended in the same direction as an angle θ of expansion of the taper waveguide 12 and has the fixed core width W, and a branch waveguide 14 which 18 separated from the waveguide 13 by a length WB at the start point of the branch waveguide 13 and is formed into a curve to have the core width gradually increased from M1 to W. Light made incident from the input waveguide 11 has the power distribution expanded by the taper waveguide 12 and is branched to branch waveguides 13 and 14. Since the branch waveguide 13 is extended in the same direction as the angle θ of expansion of the taper wavegujae 12, the wave surface of light on the taper waveguide 12 is smoothly connected to the branch waveguide 13, and the radiation loss is reduced.;COPYRIGHT: (C)1996,JPO