Publication No: 2233Search all ORC publications    

Superstrate index control of waveguide grating reflectivity

S.Pissadakis, M.N.Zervas, D.A.Sager, and J.S.Wilkinson

Abstract

Control of reflectivity of a relief grating in a high-index film overlaid on a monomode glass waveguide was achieved by adjustment of the superstrate refractive index with liquids. Weak gratings reflecting at 1531 nm were inscribed by UV laser ablation. The grating reflectivity was measured as the ratio of the transmission outside the reflection band, at 1536 nm, to that at the Bragg wavelength. Reflectivity with an air super-strate was <0.3 dB for both polarizations. In the TE polarization the grating strength increased to 20.5 dB after application of a liquid of index 1.45. In the TM polarization the strength increased to 27 dB with a superstrate index of 1.50. Good agreement was found with a theoretical model based on beam propagation.


Optics Letters (2002) Vol.27(5) pp.327-329

Southampton ePrint id: 13809

 

Click here to request a preprint of this paper. (Please mention the paper number)

 

 

 

Copyright University of Southampton 2006