Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2017 Feb 24;6(2):e16207. doi: 10.1038/lsa.2016.207

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2017 The Author(s)

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/4.0/

PMC Copyright notice

Conceptual illustration of PPDM-4 DPSK system for long-haul transmission. Insets illustrate the typical trajectory of PPDM signal transmission in the fiber and the relationship of four principal axes of two coherent receivers. OC, optical coupler.