REVIEW 1

J. of Lightwave Technology
K. O. Hill and G. Meltz
1997

"FIBER BRAGG GRATING TECHNOLOGY FUNDAMENTALS AND OVERVIEW"

1. what is FBG?
Fiber Bragg grating (FBG) is a periodic pertubation of the refractive index along the fiber length which is formed by exposure of the core to an intense optical interference pattern.

2. what is the meaning of 'photosensitivity'?
The growth in back reflected light was explained in terms of a new nonlinear effect called 'photosensitivity' which enables an index grating to be written in the fiber.

3. how does 'photosensitivity' occur?
Coherent light propagating in the fiber interferes with a small amount of light reflected back from the end of the fiber to set up a standing wave pattern which through photosensitivity write an index grating in the fiber core.