Answering Questions About Fiber Optics

Fiber Optic Technology – What it is and What it Does

What is optical fiber?

Optical fiber is defined as a glass or plastic filament that guides a light wave along its path.

What is multimode fiber?

Multimode fiber is optical fiber that permits light to travel multiple paths referred to as modes. It features a core diameter of 50 to 62.5 microns. Multimode fibers are able to transmit AV signals in short to intermediate-distance applications, such as within a building.

What is single-mode fiber?

Singlemode fiber is optical fiber allowing single path light travel, which is commonly known as the fundamental mode and features a core diameter of 8 to 9 microns. Singlemode fiber can also be used to transmit AV signals over extreme distances up to many miles or kilometers.

How is an AV signal transmitted through a fiber?

A fiber optic transmitter transforms the AV signal into an optical signal, using a VCSEL or laser diode as a light source. The glass fiber guides the optical AV signal through the path. A photodetector, in a fiber optic receiver at the far end of the fiber, transforms the optical AV signal back into an electrical AV signal.

What is a light-emitting diode?

A light-emitting diode (LED) is a semiconductor device emitting light when an electrical current passes through it. An LED emits visible light which is used in a variety of applications, including signage, area lighting, numerical displays, and indicator lights on electrical equipment. In the case of fiber optics, an LED is used as a light source for low-speed signals such as TOSLINK or 100BASE-SX Ethernet, because of its low cost. When transmitting high-speed video signals over fiber, An LED is not recommended.

What is a laser diode?

A laser diode is a semiconductor device designed to emit a narrow beam of coherent light, such as the beam of light from a laser pointer. In AV fiber optic transmitters, laser diodes are used as the light source for transmitting video, audio, and control signals.

What is a VCSEL?

A Vertical Cavity Surface Emitting Laser (VCSEL) is a special type of laser diode that has lower manufacturing costs than other types of laser diodes. It can be mass-produced with high yield rates and has a smaller PCB footprint, making it ideal for use in fiber optic transmitters to send high-resolution video, audio, and control signals.

What is a photodetector?

A photodetector is a semiconductor device designed to convert an optical signal into an electrical signal. A photodetector is used in a fiber optic receiver to convert optical AV signals.