ARRAYED WAVEGUIDE
GRATINGS
-By Shodhan Shetty
ECE-E641
Operation Principle
AWG is a complex optical circuit contained on a glass-silicon wafer about 1 or 2 inches in diameter
Arrayed Waveguides
Free
Propagation
Regions (FPRs)
Operation Principle (contd ..)
Application of Fresnel-Kirchoff diffraction integral to one of the FPRs in an AWG
R
W
A(  )
Operation Principle (contd..)

Fresnel-Kirchoff diffraction
integral
U  x,   

 j
R
x
 A e
j
2nx
R
d
x
Free Spectral Range

FSR


2
c
l. N eff
Here,
l
=Optical path length difference between adjacent array arms
Functions

WDM de(multiplexing) [1]
OADM [2]
Wavelength Routing
Signal Processing
Dispersion Compensation [3]
Optical True-time delay lines [4]
Optical Filters [5]
Femto-second pulse train generation [6]

Specifications required:

Channel Spacing
Pass band Shape
Adjacent Channel Crosstalk
Free Spectral Range










WDM de(multiplexing) and OADM
Optical Filter [7]
Optical Filter (contd.. )
Optical Delay Line [4]
Here, d is distance between
Antenna Array elements
AWG Chip
Bare AWG chip
A packaged Arrayed waveguide
Grating optical mux/demux module
References
[1] H. Yamada et al, "Measurement of Phase and Amplitude Error Distributions
in Arrayed-Waveguide Grating Multi/Demultiplexers Based on Dispersive
Waveguide", Journal of Lightwave Technol., p.1309 (2000)
[2] Y. Tachikawa, Y. Inoue, M.Kawachi, H. Takahashi, and K. Inoue,”Arrayedwaveguide grating add-drop multiplexer with loop-back optical paths,” Electron.
Lett., 1993,29,pp. 2133-2134
[3] Michael Parker, Stuart walker,” Arrayed waveguide gratings, fiber Bragg
gratings, and photonic crystals: An Isomorphic Fourier transform light
propagation analysis,” IEEE journal of selected topics in quantum electronics,
vol. 8, pp. 1158, 2002
[4] B. Vidal et al, “Novel Dispersion-based optical delay line using Arrayed
waveguide grating for antenna beamforming applications
[5] K. Okamoto,” Recent progress of integrated optics planar lightwave circuits,”
Optical quantum Electron., vol. 31, pp. 107-129,1999
[6] D.E. Leird, A.M. Weiner et al, “Generation of high repetition rate WDM pulse
trains from an Arrayed waveguide grating,” IEEE PTL, vol. 13, pp. 221, 2001
[7] Van Thourhaut et al,”Novel Geometry for an Integrated channel Selector,” IEEE
Jour. of sel. Topics in Quantum Electronics