4.4 Arrayed Waveguide Grating

Fiber Bragg Grating Reverse Filter

In this paper, we report an inverse-designed narrow-band silicon Bragg grating filter that unites lateral-misalignment apodization with cooperative particle swarm optimization (CPSO). The initial coupling-coefficient profile of the filter is first yielded by a layer-peeling algorithm. A fiber Bragg grating (FBG) is a type of distributed Bragg reflector constructed in a short segment of optical fiber that reflects particular wavelengths of light and transmits all others. It can provide stable tunable range, simple structure, high resolution, and long lifetime.

Principle of Grating Etching Fiber

The first in-fiber Bragg grating was demonstrated by in 1978. 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 inscription technique where the laser illumination came from the side of the fiber. This technique uses the interference pattern of ultraviolet laser light to create the periodic structure of the fiber Bragg grating.

Composition of waveguide array gratings

Conventional -based AWGs, as illustrated in the figure above, are lightwave circuits fabricated by depositing layers of silica on a. The AWGs consist of a number of input (1) and output (5) couplers, a free space region (2) and (4) and the grating (3). The grating waveguide.

Temperature-insensitive fiber Bragg grating

Among the diversity of optical fiber sensing technologies, temperature resistant fiber Bragg gratings are increasingly being considered for the instrumentation of future nuclear power plants, especially for components exposed to high temperature and high radiation levels. However, their temperature dependence of around +10 pm/°C is a limiting factor, making it challenging for sensors to discriminate strain from temperature. Fiber Bragg gratings (FBGs) are receiving much attention for fiber sensor applications due to their small size, absolute measurement capability, immunity to electromagnetic interference, wavelength multiplexing, and distributed sensing possibilities. Since they are readily made by controlling the.