05th July 2008
Bit error ratio (BER) measurement is the fundamental measurement of the quality of the fiber optic communication system. It measures the system's probability that transmitted bits will be correctly received as logic ones and zeros.
Bit error ratio is t...
05th July 2008
What are fiber optic sensors?
The fundamental characteristic of all fiber optic sensors is that they depend on some optical properties, such as intensity, phase, state of polarization and wavelength, to be modulated by measurands. Measurands could be p...
05th July 2008
What happens if a major fiber optic cable is cut or a major hubbing location is destroyed in a fiber network? Will the whole system be brought down?
That is the subject of this article: the survivability of a well designed fiber network.
Modern fibe...
05th July 2008
The structure of an optical receiver is simple: consisting of just a photodiode to produce the electrical current and an amplifier. But do not be fooled: it is far more complex to design a really high performance optical receiver. So we will talk about so...
05th July 2008
In the last decade, a wide variety of applications have been developed that covers a dozen of datacom networking technologies. The transmission speed ranges from 10Mbits up to 10Gbit/s and growing.
High distance-bandwidth product is the major selling p...
05th July 2008
Do you know why it is so expensive to install Fiber To The Home? Why Bell companies are reluctant to deploy fiber optic network directly to consumers in a large scale?
It's not the material cost. It's the labor! The introduction of fiber into the subsc...
20th June 2008
The History of Traditional PSTN
The traditional PSTN (Public Switched Telephone Network) has been continuously improving since its inception by Alexander Bell. There are valid reasons why PSTN exists in its current state.
What is Ring-Down
At fir...
20th June 2008
Understanding FTTH (Fiber To The Home)
FTTH is an all-fiber connection to the home which provides a minimum of 155Mbps bandwidth on both up stream and down stream directions. Basically, it is composed of a fiber from the service node to the optical spl...
20th June 2008
Why Do We Need Fiber Optic Attenuators?
A fiber optic attenuator, also called an optical attenuator, simulates the loss the would be caused by a long length of fiber. Typically, this device performs receiver testing. While an optical attenuator can sim...
20th June 2008
Why do we need fiber optic isolator?
Light can be reflected back and forth. This is also true in fiber optic communication networks. But in fiber optic networks, most of the reflections are harmful to the stability of the system which is especially tru...
20th June 2008
What is an optical circulator?
The optical circulator has similar function and design as the optical isolator. An optical circulator is an nonreciprocal passive device that directs light sequentially from port 1 to port 2, from port 2 to port 3, and so...
20th June 2008
What is all-optical switching?
All-optical switching is a process by which light, usually in the form of digital communication signals, is routed from one transmission channel to another, or modulated, without intermediate conversion to another format....
13th June 2008
When testing loss in a fiber optic link, some basic principles must be kept in mind all the time.
1.The testing wavelength should always be the same as the working wavelength. Because optical fiber loss varies with light wavelength, you will get incorr...
13th June 2008
What is WDM?
WDM is the abbreviation for Wavelength Division Multiplexing. What it does is to split the the light in an optic fiber into a number of discrete wavelengths (colors). Each wavelength (color) is a independent channel running at data rate at...
11th June 2008
The SONET standards were developed in the mid-1980s to take advantage of low-cost transmission over optical fibers. It defines a hierarchy of data rates, formats for framing and multiplexing the payload data, as well as optical signal specifications(wavel...
