The history of fiber optic telecommunication deserves a book by itself since it took several generations to get the industry today. You can get some good readings here: http://wiki.fiberoptics4sale.com/FiberOpticsHistory
Optical fiber is a long thin cylindrical fiber made from glass or plastic, as tiny as one tenth of a human hair. A standard telecom optical fiber is composed of three cylindrical layers, counted inside out: fiber core (diameter 8~10um), cladding (diameter 125um) and buffer coating (diameter 900um).
Fiber core and cladding is made from glass or silica. Fiber Core and cladding layers work together to confine the light inside the core without leaking. Fiber buffer coating is made from acrylic or plastic and provides handling flexibility and physical protection for the fiber.
Optical fibers utilize an optical phenomenon called total internal reflection. When light is injected into the fiber from end face, it is confined inside the core without leaking outside and losing its energy.
Then light is digitally modulated to represent 1 and 0 just like a computer, so information can be carried from one site to another site which may be from San Francisco all the way to New York.
What are fiber optic connectors and how do they work?
Now you know how optical fibers work. So what is a fiber optic connector and what's its function in a fiber optic telecommunication network?
Put it simple, a fiber optic connector's function is just like an electric power plug, it connects light from one section of optical fiber to another section of optical fiber.
Since optical fibers are so tiny, fiber optic connectors have to be made with high precision, at the scale of 0.1um which is one hundredth of a human hair.
Fiber optic connectors align two fibers end to end so precisely that light can travel from one fiber into another without bouncing off the interface and loss its signal.
Besides, fiber optic connectors provide cross connect flexibility for the telecommunication network. So a complicated computer network could be made modular and easy to manage.
Just like any other connectors used in electric industry, electronic industry and computer industry, many different kinds of fiber optic connectors were invented along the development of fiber optic communication industry. Some of them once were very popular in the industry and now have served their purposes and are fading away.
The most popular fiber optic connectors used nowadays are SC, ST, LC, FC, MTRJ, SMA and a few of other less popular ones. Sure you will see new connectors invented with the progress of this industry.
Here is another fiber optic connector tutorial which you may be interested in: http://www.fiberoptics4sale.com/Merchant2/fiber-optic-connectors.php
Another fact is that fiber optic connections are harder to trouble shoot in case of service outage. For this reason, please learn carefully on how to clean a fiber optic connector as below.
Cleaning Method Choices
Fiber connector cleaning sometimes can get confusing since too many methods are affable and every single vendor says they are the best. Now let's examine it one by one.
:: Compressed Gas
Compressed air is also referred to as "canned air". It is used to blow dust from fiber connector end face.
Advantages: The least expensive and effective for large dry particles. Non-abrasive approach which won't scratch the connector.
Disadvantages: Has little or no effect on particles below 3 microns in diameter. And proved to be ineffective if the contamination includes oil, fingerprints, dried solvent residue, etc.
:: Lint-free wipe and solvent
This was the first developed approach for cleaning fiber connectors. The oldest one used some sort of lens paper, cloth and sometimes solvent to clean. The most common solvent is IPA which tends to leave a residue as it dries slowly and dissolved/suspended solid are left behind.
Advantages: Cheap, work well if trained properly. New types of solvents which leave almost no residue are becoming more popular.
Disadvantages: Unreliable. Largely depends on technician's skill.
To properly clean fiber connectors utilizing the wipe and solvent method, follow the procedure below:
Step 1 Using a Kim Wipe and cleaning solvent, moisten the wipe by placing on top of the solvent and push down 3 times, this will saturate the wipe.
Step 2 Once the wipe is saturated, place on a work surface with a second (dry) wipe.
Step 3 Wipe the connector, end face down on moist wipe (this will remove most of the large contaminates). Follow by repeating process on the dry wipe, with a minimum of 3 strokes per connector (more may be necessary)
Step 4 Once complete, insert connector into a optical microscope to verify connector cleanliness. If connector does not pass visual inspection, repeat process from [Step 2 - Step 4]
:: Swab and solvent
There are two types of popular swabs in the fiber optic industry: general purpose and special built.
The general purpose swabs are cheap but very unreliable. The special built swabs are much better but this is still a highly iterative approach.
To properly clean fiber connectors, receptacles, adapters, and other fiber connection points utilizing the swab and solvent cleaning method, follow the procedure below:
Step 1 Using a cleaning swab and cleaning solutioin, moisten the swab by placing it on top of the solvent dispenser, place your finger over the swab tip and push down 1 time, this will saturate the swab.
Step 2 Recessed connection points: Once saturated, insert the moistened swab into the receptacle, adapter, or other connection point and rotate the tip back and forth 1/4 turn 10 times while applying various pressure.
Step 3 Exposed connection points: Once saturated, rotate the tip 10 revolutions around the connector while applying various pressure.
Step 4 Once complete, insert connector into a optical microscope to verify connector cleanliness. If connector does not pass visual inspection, repeat process from [Step 2]
:: Connector Reel cleaner
Two primary brands exist on the market for reel connector cleaners: Cletop and Optipop. There are other brands available but not as popular as these two.
The reel cleaner has a ratcheting mechanism, sliding dust cover, resilient pad, and replace tape reel.
To properly clean fiber connectors utilizing the Cletop cleaning system, follow the procedure below:
Step 1 Using the single fiber or MT ferrule Cletop cleaning system, advance the cleaning tape by pressing and holding the green button located on the bottom of the cartridge.
Step 2 Holding down the green button, wipe the connector, end face down, in the direction indicated on the cartridge.
Step 3 Insert the connector into an optical microscope to verify connector cleanliness.
Step 4 If connector does not pass visual inspection, repeat process from [Step 1 - Step 3]