Arrayed waveguide grating
Arrayed waveguide gratings (AWG) are commonly used as
transmission capacity of optical networks considerably.[1]
The devices are based on a fundamental principle of
demultiplexers to retrieve individual channels of different wavelengths at the receiving end of an optical communication network.[1]
Operation of AWG devices
Conventional
planar lightwave circuits fabricated by depositing layers of doped and undoped silica on a silicon substrate
.
The AWGs consist of a number of input (1) and output (5) couplers, a free space
propagation region (2) and (4) and the grating waveguides
(3). The grating waveguides consists of many waveguides, each having a constant length increment (ΔL).
- Light is coupled into the device via an optical fiber (1) connected to the input port.
- Light diffracting out of the input waveguide at the coupler/slab interface propagates through the free-space region (2) and illuminates the grating with a Gaussian distribution.
- Each wavelength of light coupled to the grating waveguides (3) undergoes a constant change of phase attributed to the constant length increment in grating waveguides.
- The diffracted light from each waveguide within the grating undergoes phase shift induced by the constant length increment in the grating waveguides.[2]
References
- ^ a b Paschotta, Dr Rüdiger. "Arrayed waveguide gratings". RP Photonics AG. Retrieved 2023-06-15.
- ^ Hecht, Jeff (2015). Understanding Fiber Optics.