Coupled Resonator Optical Waveguides (CROWs) Fatemeh Soltani Fatemeh.soltani@mail.mcgill.ca McGill...

Coupled Resonator Optical Waveguides (CROWs)

Fatemeh SoltaniFatemeh.soltani@mail.mcgill.caMcGill UniversityPhotonics Systems GroupCMC workshop, July 2012

An Illustration of CROW

2Scheuer, G. T. Paloczi, J. K. S. Poon and A. Yariv, “Coupled Resonator Optical Waveguides: Towards Slowing and Storing of Light”, Opt. Photon. News, Vol. 16 (2005) 36

Why CREW ?• Engineer the dispersion properties of a CROW

• The ability to realize ultra-slow group velocities

• Applications in delay lines, optical memories and all-optical switching.

• Simple analytic expressions for the time delay, usable bandwidth and overall losses in CROW delay lines.

• Good quantitative agreement between the theoretical transmission function obtained by transfer matrix formalism.

• The measurement of a CROW interferometer realized in polymer material.

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Travelling wave in a finite CROW

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Exact dispersion relations [ for 20 resonator (solid) and an infinite (dash-dot) CROWs.]

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Tradeoffs

Tradeoffs among delay, losses and bandwidth for a CROW consisting of 10 coupled ring resonators having a FSR of 310 GHz and propagation loss of 4 dB/cm

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Experimental Process

a) An optical micrograph of the CROW-MZI and an SEM zoom on the coupling region b) A theoretical fit (dashed) and a measurement (solid) of the CROW-MZI transmission. The fit parameters are κ=0.46 and loss of 30dB/cmc) A CROW consisting of 25 resonators

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My suggestions1 2 3

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Challenges• Are these geometric suggestions doable in

software or later in fabrication? • Design challenges• Fabrication challenges• Testing challenges• Ideas for coupling

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Example of ongoing research

From Nanophotonics Lab. (Dr. Jacob Scheuer, Caltech)

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Suggestions / Questions ?

Thanks you for you emails / comments !

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