Arrayed Waveguide Gratings | previous | next | feedback |
Acronym: AWG
Definition: optical filter or multiplexer device based on arrays of waveguides
An arrayed waveguide grating is a (typically fiber-coupled) device which can separate or combine signals with different wavelengths. It is usually built as a planar lightwave circuit, where the light coming from an input fiber first enters a multimode waveguide section, then propagates through several single-mode waveguides to a second multimode section, and finally into the output fibers. Wavelength filtering is based on an interference effect and the different optical path lengths in the single-mode waveguides: any frequency component of the input propagates through all single-mode waveguides, and the output in any channel results from the superposition (interference) of all these contributions. The wavelength-dependent phase shifts lead to a wavelength-dependent overall throughput.
Figure 1: Structure of an arrayed waveguide grating.
Applications
Arrayed waveguide gratings are mainly applied in optical fiber communication systems, in particular in those based on multi-channel transmission with wavelength division multiplexing, where individual wavelength channels must be combined or separated. An arrayed waveguide grating may also be used for separating the lines in the spectrum of a supercontinuum source.
Bibliography
| [1] | C. Dragone, “An N × N optical multiplexer using a planar arrangement of two star couplers”, IEEE Photon. Technol. Lett. 3 (9), 812 (1991) |
| [2] | S. Chandrasekhar et al., “Monolithic eight-wavelength demultiplexed receiver for dense WDM applications”, IEEE Photon. Technol. Lett. 7 (11), 1342 (1995) |
See also: optical filters, wavelength division multiplexing
