1. ARRAYED WAVEGUIDE GRATINGS
-By Shodhan Shetty
ECE-E641

2. Operation Principle Arrayed Waveguides Free Propagation Regions (FPRs)
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)

3. Operation Principle (contd ..)
Application of Fresnel-Kirchoff diffraction integral to one of the FPRs in an AWG R W
A( )

4. Operation Principle (contd..)
Fresnel-Kirchoff diffraction integral
Free Spectral Range
Here,
=Optical path length difference between adjacent array arms

5. Functions Specifications required: 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

6. WDM de(multiplexing) and OADM

7. Optical Filter [7]

8. Optical Filter (contd.. )

9. Optical Delay Line [4] Here, d is distance between
Antenna Array elements

10. AWG Chip A packaged Arrayed waveguide Bare AWG chip
Grating optical mux/demux module
Bare AWG chip

11. 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,”Arrayed-waveguide grating add-drop multiplexer with loop-back optical paths,” Electron. Lett., 1993,29,pp
[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 ,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