Summary: <p>Mike Hoffman and <a href="https://twitter.com/Keysight_Daniel">Daniel Bogdanoff</a> continue their discussion with Stefan Loeffler about optical communication. In the first episode, we looked at “what is optical communication?” and “how does optical communication work?” This week we dig deeper into some of the latest optical communication techniques and advances in the industry as well as the use of fiber optic cable in electronics and long-range telecommunication networks.</p> <p><a href="https://youtu.be/sZXxltWJwIU">Video</a> version (<a href="http://www.youtube.com/keysightoscilloscope">YouTube</a>):</p> <div class="jetpack-video-wrapper"></div> <p> </p> <p>Audio Version:</p> <audio class="wp-audio-shortcode" id="audio-445-24" style="width: 100%;"><a href="https://eestalktech.com/wp-content/uploads/2017/06/copper-vs-fiber-optic-cable-and-optical-communication-techniques-ees-talk-tech-11.mp3">https://eestalktech.com/wp-content/uploads/2017/06/copper-vs-fiber-optic-cable-and-optical-communication-techniques-ees-talk-tech-11.mp3</a></audio> <p> </p> <h2><strong>Discussion Overview:</strong></h2> <p> </p> <h3><strong>Installation of optical fiber and maintenance of optical fiber</strong></h3> <p>We can use<a href="http://eestalktech.com/2017/05/16/optical-101/"> optical communication</a> techniques such as phase multiplexing</p> <p>There’s a race between using more colors and higher bitrates to increase data communication rates.</p> <p>Indium doped fiber amplifiers can multiply multiple channels at different colors on the same optical PHY.</p> <p>You can use up to 80 colors on a single fiber optic channel! 3:52</p> <p>How is optical communication similar to RF? Optical communication is a lot like WiFi 4:07</p> <p>Light color in optical fiber is the equivalent of carrier frequencies in RF</p> <p> </p> <h3><strong>How do we increase the data rate in optical fiber?</strong></h3> <p>There are many multiplexing methods such as multicore, wavelength division, and polarization 4:50</p> <p>Practically, only two polarization modes can be used at once. The limiting factor is the separation technology on the receiver side. 6:20</p> <p>But, this still doubles our bandwidth!</p> <p>What about <a href="https://en.wikipedia.org/wiki/Dark_fibre">dark fiber</a>? Dark fiber is the physical piece of optical fiber that is unused. 7:07</p> <p>Using dark fiber on an existing optical fiber is the first step to increasing fiber optic bandwidth.</p> <p>But wavelengths can also be added.</p> <p>Optical C-band vs L-band 7:48</p> <p>Optical C-band was the first long-distance band. It is now joined by the L-band.</p> <p>Is there a difference between using different colors and different wavelengths?</p> <p>Optical fibers are a light show for mosquitos! 8:30</p> <p> </p> <p>How do we fix optical fibers? 10:36</p> <p>For short distances, an OTDR or visual light fault detectors are often used by sending red light into a fiber and lights up when there’s a break in the fiber</p> <p> </p> <p>Are there other ways to extend the amount of data we can push through a fiber? 11:35</p> <p>Pulses per second can be increased, but we will eventually bleed into neighboring channels</p> <p>Phase modulation is also used</p> <p><a href="https://en.wikipedia.org/wiki/Pulse-amplitude_modulation">PAM-4</a> comes into play with coding (putting multiple bits in a symbol)</p> <p>And <a href="https://en.wikipedia.org/wiki/Quadrature_amplitude_modulation">QAM</a> which relies on both amplitude and phase modulation</p> <p><a href="http://www.keysight.com/main/application.jspx?id=2539363&cc=US&lc=eng&cmpid=zzfindpam4">PAM-4 test solutions</a></p> <p>How do we visualize optical fibers? 14:05</p> <p>We ca</p>
