Polarization Division Multiplexing for Optical Data Communications

Multiple parallel channels are ubiquitous in optical communications, with spatial division</p>multiplexing (separate physical paths) and wavelength division multiplexing (separate optical</p>wavelengths) being the most common forms. In this research work, we investigate the viability</p>of polarization division multiplexing, the separation of distinct parallel optical communication</p>channels through the polarization properties of light. We investigate polarization division</p>multiplexing based optical communication systems in five distinct parts.</p>In the first part of the work, we define a simulation model of two or more linearly polarized</p>optical signals (at different polarization angles) that are transmitted through a common</p>medium (e.g., air), filtered using aluminum nanowire optical filters fabricated on-chip, and</p>received using individual silicon photodetectors (one per channel). The filter model is based</p>upon an input optical signal formed as the sum of the Stokes vectors for each individual</p>channel, transformed by the Mueller matrix that models the filter proper, resulting in an</p>output optical signal that impinges on each photodiode. The simulation results show that</p>two and three channel systems can operate with a fixed-threshold comparator in the receiver</p>circuit, but four channel systems (and larger) will require channel coding of some form. The entire simulation model is designed in Cadence tools and the receiver (including optics) is</p>compatible with standard CMOS fabrication processes.</p>In the second part of the work, we design and manufacture a two channel chip that is used</p>as the light receiver to confirm the simulation results from the first part of the research.</p>Since logistics for the receiver’s chip testing were not favorable we constrained our testing</p>to single channel operation, which we demonstrated functionality using both electrical and</p>optical inputs. In addition, we used data from a pair of optical imagers (one linear and the</p>second with a logarithmic response) to investigate the noise properties of both the optical</p>and electrical signals within the system.</p>In the third part of the work, we provide examples of channel coding that enable the four</p>channel system to operate with positive noise margins.</p>In the fourth part of the work, we define an end-to-end simulation model of two, three or</p>four channel systems that utilize air, fiber, and a pair of mirrors in the optical path from</p>transmitter to receiver. Each of these systems is shown to have positive noise margins (albeit</p>using channel coding on the four channel editions); however, there are many circumstances</p>where the noise margins are quite small.</p>In the final part of the work, we examine the trade-offs between number of channels, signal</p>power, and noise margins, including the use of pulse amplitude modulation within the two</p>channel system.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Computer Science & Engineering

Year dc:date.available

2019

Author dc:creator

• Ivanovich, Darko

Contributors dc:contributor

• Roger D. Chamberlain
• Shantanu Chakrabartty, Viktor Gruev, Ulugbek Kamilov, Richard Livingston,

• Computer Engineering
• Electrical and Electronics
• Optics

Statement dc:rights

• I have not registered my thesis with the U.S. Copyright Office, but intend to later.

Language dc:language

English (en)

Identifier

https://openscholarship.wustl.edu/eng_etds/474

OAI identifier oai:identifier

oai:openscholarship.wustl.edu:eng_etds-1519