An experimental study to discriminate between the validity of diffraction theories for off-Bragg replay

We show that experiments clearly verify the assumptions made by the first-order two-wave coupling theory for one dimensional lossless unslanted planar volume holographic gratings using the beta-value method rather than Kogelnik's K-vector closure method. Apart from the fact that the diffraction process is elastic, a much more striking difference between the theories becomes apparent particularly in the direction of the diffracted beam in off-Bragg replay. We therefore monitored the direction of the diffracted beam as a function of the off-Bragg replay angle in two distinct cases: [a] the diffracted beam lies in the plane of incidence and [b] the sample surface normal, the grating vector and the incoming beam do not form a plane which calls for the vectorial theory and results in conical scattering.Comment: Corrected Eqs. (3) & (6); 14 pages, 8 figure

Forward Brillouin Scattering In Tapered Optical Fibers

We experimentally study forward Brillouin scattering in tapered fibers. Circularly symmetric acoustic phonons resonant in fibers are observed by using a novel photoacoustic measurement technique. Strong acousto-optic interaction can take place in highly tapered fibers. © 2008 Optical Society of America.Dainese, P., Russell, P.S.J., Wiederhecker, G.S., Joly, N., Fragnito, H.L., Laude, V., Khelif, A., Raman-like light scattering from acoustic phonons in photonic crystal fiber (2006) Opt. Express, 14, pp. 4141-4150Elser, D., Andersen, U.L., Korn, A., Glöckl, O., Lorenz, S., Marquardt, C., Leuchs, G., Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers (2006) Phys. Rev. Lett., 97, p. 133901Beugnot, J., Silvestre, T., Maillotte, H., Mélin, G., Laude, V., Guided acoustic wave Brillouin scattering in photonic crystal fibers (2007) Opt. Lett., 32, pp. 17-19Shelby, R.M., Levenson, M.D., Bayer, P.W., Guided acoustic-wave Brillouin-scattering (1985) Phys. Rev. B, 31, pp. 5244-525

Coherent Control Of Ultra-high Frequency Acoustic Resonances In Photonic Crystal Fibers

Acoustic resonances trapped within the glass core (1 μm diameter) of a photonic crystal fibre are excited electrostrictively using laser pulses. Using pulse sequences they can be coherently controlled leading to a 100-fold increase in their amplitude. © 2008 Optical Society of America.Heberle, A.P., Ultrafast coherent control and destruction of excitons in quantum-wells (1995) Physical Review Letters, 75 (13), pp. 2598-2601Feurer, T., Vaughan, J.C., Nelson, K.A., Spatiotemporal coherent control of lattice vibrational waves (2003) Science, 299 (5605), pp. 374-377Biryukov, A.S., Excitation of sound waves upon propagation of laser pulses in optical fibres (2002) Quantum Electronics, 32 (9), pp. 765-775Dainese, P., Raman-like light scattering from acoustic phonons in photonic crystal fiber (2006) Optics Express, 14 (9), pp. 4141-4150Wiederhecker, G.S., Coherent control of ultra-high frequency acoustic resonances in photonic crystal fibers (2007), arXiv:0711.4365Marcuse, D., Coupled-mode theory for anisotropic optical. waveguides (1975) Bell System Technical Journal, pp. 985-99

Controlling Acousto-optic Interactions In Photonic Crystal Fiber With Sub-wavelength Core-hole

The quasi-Raman interaction between confined acoustic phonons and light in PCF is strongly altered by the introduction of a sub-wavelength hole running axially through the core. Coupling calculations and forward scattering spectra illustrate the effect. ©2007 Optical Society of America.Dainese, P., Raman-like light scattering from acoustic phonons in photonic crystal fiber (2006) Opt. Express, 14, pp. 4141-4150Beugnot, J.C., Experimental observation of core guided acoustic wave Brillouin scattering in photonic crystal fibres (2006), in ECOCDainese, P., Stimulated Brillouin scattering from multi-GHz-guided acoustic phonons in nanostructured photonic crystal fibres (2006) Nature Physics, 2, pp. 388-392Elser, D., Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers (2006) Phys. Rev. Lett., 97, p. 133901Work done in a collaboration between CePOF and the University of Bath-submitted for publicationShelby, R.M., Levenson, M.D., Bayer, P.W., Guided acoustic-wave Brillouin scattering (1985) Phys. Rev. B., 31, pp. 5244-5252Yariv, A., Yeh, P., Propagation and control of laser radiation (1984), (John Wiley & Sons, Chap.

Wavelength dependence of induced nonlinear effects in photonic crystal fibre

Summary form only given. In this paper, we report a systematic study of spectral effects at various wavelengths relative to the zero group velocity dispersion (GVD) point in the fibre. The fibres used in our experiments had core diameters of 1.6 /spl mu/m and 2.5 /spl mu/m corresponding to a zero GVD point at 680 nm and 790 nm, respectively. Light from a 10 fs Ti:sapphire laser, centred on 800 nm, was coupled into both of these fibres and the smaller core fibre produced a spectrum corresponding to a four-wave mixing peak in the visible portion of the spectrum and a soliton self-frequency-shifted spectral feature in the near infra-red. The larger core fibre produced an almost continuous spectrum