Polarization reducing apparatus, light source apparatus, optical amplifying apparatus, and excitation light source apparatus for raman amplification

Patent metadata

Field	Value
Publication number	US-2016341900-A1
Application number	US-201615228575-A
Country	US
Kind code	A1
Filing date	Aug 4, 2016
Priority date	Mar 19, 2012
Publication date	Nov 24, 2016
Grant date	—

Abstract

A polarization reducing apparatus includes a separating unit configured to separate input light into components having polarization directions orthogonal to each other; a winding waveguide of silicon formed on a silicon substrate in a winding manner, the winding waveguide transmitting a first component among the components separated by the separating unit; an optical path configured to have a shorter optical path length than the winding waveguide, the optical path transmitting a second component among the components separated by the separating unit; a combining unit configured to combine the first component and the second component; and an output unit configured to output light consisting of the first component and the second component combined by the combining unit.

First claim

What is claimed is:

1 . A polarization reducing apparatus comprising:
a separating unit configured to separate input light into components having polarization directions orthogonal to each other; a winding waveguide of silicon formed on a silicon substrate in a winding manner, the winding waveguide transmitting a first component among the components separated by the separating unit; an optical path configured to have a shorter optical path length than the winding waveguide, the optical path transmitting a second component among the components separated by the separating unit; a combining unit configured to combine the first component and the second component; and an output unit configured to output light including the first component and the second component combined by the combining unit,
wherein the separating unit, the optical path, and the combining unit are silicon waveguides formed on the silicon substrate.

2 . The polarization reducing apparatus according to claim 1 , further comprising
a waveguide formed on the silicon substrate, in proximity to the optical path, and inducing an optical loss on the second component transmitted through the optical path.

3 . The polarization reducing apparatus according to claim 1 , further comprising
a branch interference unit configured to have parallel waveguides that branch the second component transmitted through the optical path and respectively transmit branches that result, the branch interference unit causing interference of the branches transmitted through the parallel waveguides before outputting the braches to the combining unit, and a temperature adjusting unit configured to adjust a temperature difference between the parallel waveguides.

Assignees

• Fujitsu Ltd

Inventors

• Onaka Miki

Classifications

• H01S3/1003

  tunable optical elements, e.g. acousto-optic filters, tunable gratings · CPC title

• G02B6/29395

  configurable, e.g. tunable or reconfigurable (switching G02B6/35) · CPC title

• G02B6/29397

  Polarisation insensitivity · CPC title

• G02B6/126

  using polarisation effects {(G02B6/1226 takes precedence)} · CPC title

• G02B6/272

  comprising polarisation means for beam splitting and combining · CPC title