Search results
Results From The WOW.Com Content Network
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. This is achieved by creating a periodic variation in the refractive index of the fiber core, which generates a wavelength-specific dielectric mirror .
Time-resolved simulation of a pulse reflecting from a Bragg mirror. A distributed Bragg reflector (DBR) is a reflector used in waveguides, such as optical fibers.It is a structure formed from multiple layers of alternating materials with different refractive index, or by periodic variation of some characteristic (such as height) of a dielectric waveguide, resulting in periodic variation in the ...
where m is the Bragg order (a positive integer), λ B the diffracted wavelength, Λ the fringe spacing of the grating, θ the angle between the incident beam and the normal (N) of the entrance surface and φ the angle between the normal and the grating vector (K G). Radiation that does not match Bragg's law will pass through the VBG undiffracted.
Increasing current in the gain region causes a red shift in laser output due to heating. The reflectivity curve of the passive grating does not change. As a result, the grating will experience loss of reflectivity at the longer wavelengths, and eventually will induce a discontinuous blue shift in the wavelength to find a higher gain mode.
The structure builds a one-dimensional interference grating (Bragg scattering), and the grating provides optical feedback for the laser. This longitudinal diffraction grating has periodic changes in refractive index that cause reflection back into the cavity. The periodic change can be either in the real part of the refractive index or in the ...
The reflectivity of a dielectric mirror is based on the interference of light reflected from the different layers of a dielectric stack. This is the same principle used in multi-layer anti-reflection coatings , which are dielectric stacks which have been designed to minimize rather than maximize reflectivity.
A Bragg grating is an example of this type of photonic crystal. One-dimensional photonic crystals can include layers of non-linear optical materials in which the non-linear behaviour is accentuated due to field enhancement at wavelengths near a so-called degenerate band edge.
Fiber Bragg grating based fiber-optic sensors significantly enhance performance, efficiency and safety in several industries. With FBG integrated technology, sensors can provide detailed analysis and comprehensive reports on insights with very high resolution.