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Abstract:The propagation of 300 femtosecond optical pulses in Silicon-on Insulator waveguides has been studied by means of a pump-probe set-up. The ultrafast pulses allowed the observation of large Kerr-induced red and blue shifts (9nm and 15nm, respectively) of the probe signal depending on the delay between pump (1554nm) and probe (1683nm) pulses. A numerical model taking into account the Kerr effect, Two Photon Absorption and Free Carrier Absorption is presented and provides good agreement with our experimental data and data in literature. A microring resonator based device is proposed that exploits the observed wavelength shift for sub-picosecond all-optical switching. ©2006 Optical Society of America O. Boyraz, P. Koonath, V. Raghunathan, and B. Jalali, "All optical switching and continuum generation in silicon waveguides," Opt. Express 12, 4094-4102 (2004

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We demonstrate high-speed all-optical switching via vertical excitation of an electron-hole plasma in an oxygen-ion implanted silicon-on-insulator microring resonator. Based on the plasma dispersion effect the spectral response of the device is rapidly modulated by photoinjection and subsequent recombination of charge carriers at artificially introduced fast recombination centers. At an implantation dose of 1 x 10(12) cm(-2) the carrier lifetime is reduced to 55 ps, which facilitates optical switching of signal light in the 1.55 mum wavelength range at modulation speeds larger than 5 Gbits/s.

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The lasing properties of an optimized two-dimensional photonic crystal structure with an organic gain material are investigated. The feedback structure which is fabricated in a thin film of Ta2O5 increases both the index contrast from the gain material as well as the optical confinement. By combining first-order and second-order photonic crystal structures, losses occuring at the edge of the second order structure are dramatically reduced leading to a lower laser threshold and/or to a much smaller footprint of the laser.

We present experimental investigations of grating mirrors with high diffraction efficiencies exceeding 99.7% in the -1st order for TE polarization at a wavelength of 1060 nm, and exceeding a diffraction efficiency of 99% in the wavelength range from 1025 nm to at least 1070 nm. The total efficiency of a four-pass compressor for chirped pulse amplification was >96%. The design, fabrication, and characterization of the fully dielectric grating mirrors are presented.