List of Division publications with links

2009-11-01 10:07 - Influence of air-filling fraction on forward Raman-like scattering by transversely trapped acoustic resonances in photonic crystal fibers

A. Brenn, G. S. Wiederhecker, M. S. Kang, H. Hundertmark, N. Joly, and P. St.J. Russell, Journal of Optical Society of America B, Vol. 26, No. 8, pp. 1641-1648 (2009).

Raman-like forward scattering by acoustic phonons transversely trapped in birefringent silica-air photonic crystal fibers is studied. As the air-filling fraction increases, core-confined acoustic resonances become increasingly apparent at higher frequencies (>1.1 GHz), while the number of cladding-confined acoustic modes involved in scattering falls. Two main types of scattering are observed: intramodal (scattering to new frequencies within the same optical mode) and intermodal (frequency-shifted scattering to a different optical mode). It is shown that the twofold symmetric microstructure in a birefringent fiber causes strongly polarization-dependent intramodal scattering. Good agreement is obtained between the experimental measurements and numerical solutions of both the acoustic and electromagnetic wave equations by using a full-vectorial finite-element approach. Phononic bandgaps are found to play a significant role at higher air-filling fractions, leading to the appearance of additional bands in the scattering spectrum.