Category Archives: Fiber Optics

In this post, I will be showing how we model the effect of small amounts of dispersion as a power loss. We commonly refer to this power loss at the dispersion power penalty. I will also show how the need to limit the power penalty drives a critical laser parameter, the laser spectral width. Continue reading →

Lightning is a tough problem. All of my personal electronic systems are well grounded and have the best surge protection I can buy. Yet I still suffer occasional losses due to lightning – for example, this weekend I replaced a surge-blown power adapter at my cabin in northern Minnesota. Intuitively, you would think that fiber optic systems should be better protected against lightning strikes than copper-based systems because glass fiber does not conduct electricity. This is not necessarily true. Continue reading →

I was looking at some photographs of a fiber-optic deployment, and I thought you might find it interesting seeing the details of what goes into the "green yard furniture" that quietly sits in the yards of many people (Figure 1). The fiber electronics is slung on a metal bar above the hole in the ground – all the cabling comes up from the hole. The plastic green cover behind the hole is intended to provide some environmental protection and a decent appearance. Continue reading →

I recently was asked to explain how a Fiber-To-The-Premises (FTTP) system measures the length of fiber between the central office and each residence in the network (Figure 1). This is an interesting question and I thought it would be worthwhile to the describe the measurement process here. Continue reading →

I received an email today about a deployment issue that involved the reflection of light from unterminated connectors. When light travels down a fiber and encounters a change in the index of refraction, part of the energy will reflect back toward the transmitter because of a phenomenon called Fresnel reflection, which I define below (source). Continue reading →

I am at the Optical Fiber Conference in Los Angeles this week and learning a lot. This morning I attended a great talk submarine fiber optic cables given by Neal Bergano, CTO of TE Connectivity Subcom. I thought I would put my notes on blog for others to view. I was not able to find a copy of Neal's presentation, so I will replicate my notes on his presentation here. Where possible, I will include supporting information that I located on the web. Any errors introduced are mine. Continue reading →

Quote of the Day Even if all others do - not I. — Father of Joachim Fest (German Historian), from the Gospel of Matthew, a quote he made his sons memorize during WW2. I have been working for the past … Continue reading →