Optical receiver and optical axis alignment method thereof

Patent metadata

Field	Value
Publication number	US-9780884-B2
Application number	US-201414310846-A
Country	US
Kind code	B2
Filing date	Jun 20, 2014
Priority date	Jun 24, 2013
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An optical receiver comprises a package provided with an input window; a polarization-maintaining optical fiber fixable to the input window; a polarization beam splitter, disposed on the package, for inputting light outputted from the polarization-maintaining optical fiber and outputting first output light and second output light having respective polarization directions different from each other; a beam splitter, disposed on the package, for splitting the first output light; a first light-receiving element, optically coupled to the beam splitter, having two light-receiving parts corresponding to two kinds of the output light split by the beam splitter; and a second light-receiving element, disposed on the package, for receiving the second output light.

First claim

What is claimed is:

1. An optical axis alignment method of an optical receiver comprising a package provided with an input window, the package comprising a polarization beam splitter, a first optical-electrical signal converter, and a second optical-electrical signal converter; a polarization-maintaining optical fiber fixable to the input window; the method comprising:
a first step of adjusting an angle of the polarization-maintaining optical fiber according to results of detection by the first optical-electrical signal converter and the second optical-electrical signal converter;
a second step of removing the polarization beam splitter, the first optical-electrical signal converter, and the second optical-electrical signal converter from the package while keeping the angle of the polarization-maintaining optical fiber.

2. An optical axis alignment method according to claim 1 , the polarization beam splitter for inputting light outputted from the polarization-maintaining optical fiber and outputting first output light as TE-polarized light and second output light as TM-polarized light, the method further comprising:
a third step of mounting a polarizer for inputting the TE-polarized light outputted from the polarization-maintaining optical fiber and another optical-electrical signal converter for receiving output light from the polarizer onto the package while keeping the angle of the polarization-maintaining optical fiber; and
a fourth step of aligning optical axes of the polarization-maintaining optical fiber, polarizer, and the another optical-electrical signal converter while keeping the angle of the polarization-maintaining optical fiber.

3. An optical axis alignment method according to claim 1 , wherein for the first step, a light is input in the polarization-maintaining optical fiber from an external local oscillator light.

Assignees

• Sumitomo Electric Industries

Inventors

• Takechi Masaru

Classifications

• H04B10/6151

  comprising a polarization controller at the receiver's input stage · CPC title

• H04B10/614 Primary

  comprising one or more polarization beam splitters, e.g. polarization multiplexed [PolMux] X-PSK coherent receivers, polarization diversity heterodyne coherent receivers (H04J14/06 takes precedence) · CPC title