Fiber Optic Wiki

Fiber Bragg grating Manufacture(1)

June 28, 2011

The first in-fiber Bragg grating was demonstrated by Ken Hill in 1978.[1] Initially, the gratings were fabricated using a visible laser propagating along the fiber core. In 1989, Gerald Meltz and colleagues demonstrated the much more flexible transverse holographic technique where the laser illumination came from the side of the fiber. This technique uses the interference pattern of ultraviolet laser light[2] to create the periodic structure of the Bragg grating.

Fiber Bragg grating Manufacture(2)

June 28, 2011

Point-by-point.A single UV laser beam may also be used to 'write' the grating into the fiber point-by-point. Here, the laser has a narrow beam that is equal to the grating period. This method is specifically applicable to the fabrication of long period fiber gratings. Point-by-point is also used in the fabrication of tilted gratings.

Fiber Bragg grating: Types of gratings(1)

June 28, 2011

Standard gratings or Type I gratings.Written in both hydrogenated and non-hydrogenated fiber of all types Type I gratings are usually known as standard gratings and are manufactured in fibers of all types under all hydrogenation conditions. Typically, the reflection spectra of a type I grating is equal to 1-T where T is the transmission spectra. This means that the reflection and transmission spectra are complementary and there is negligible loss of light by reflection into the cladding or by absorption. Type I gratings are the most commonly used of all grating types, and the only types of grating available off-the-shelf at the time of writing.

Fiber

June 27, 2011

Fiber (also spelled fibre) is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.

Natural fibers

June 27, 2011

Natural fibers include those produced by plants, animals, and geological processes. They are biodegradable over time. They can be classified according to their origin:

Man-made fibers

June 27, 2011

Synthetic or man-made fibers generally come from synthetic materials such as petrochemicals. But some types of synthetic fibers are manufactured from natural cellulose, including rayon, modal, and the more recently developed Lyocell. Cellulose-based fibers are of two types, regenerated or pure cellulose such as from the cupro-ammonium process and modified cellulose such as the cellulose acetates.

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