Philippe Velha

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We experimentally demonstrate an ultra high Q/V nanocavity on SOI substrate. The design is based on modal adaptation within the cavity and allows to measure a quality factor of 58.000 for a modal volume of 0.6(lambda/n)(3) . This record Q/V value of 10(5) achieved for a structure standing on a physical substrate, rather than on membrane, is in very good(More)
A chalcogenide-assisted silicon waveguide is realized by depositing a thin layer of A(2)S(3) glass onto a conventional silicon on insulator optical waveguide. The photosensitivity of the chalcogenide is exploited to locally change the optical properties of the waveguide through exposure to visible light radiation. Waveguide trimming is experimentally(More)
We design compact (a few wavelength long) and efficient (>99%) injectors for coupling light into slow Bloch modes of periodic thin film stacks and of periodic slab waveguides. The study includes the derivation of closed-form expressions for the injection efficiency as a function of the group-velocity of injected light, and the proof that 100% coupling(More)
We demonstrate here that switching and tuning of a nanocavity resonance can be achieved by approaching a sub-micrometer tip inside its evanescent near-field. The resonance energy is tuned over a wide spectral range (Deltalambda/lambda~10(-3)) without significant deterioration of the cavity peak-transmittance and of the resonance linewidth. Such a result is(More)
A circuit for the management of any arbitrary polarization state of light is demonstrated on an integrated silicon (Si) photonics platform. This circuit allows us to adapt any polarization into the standard fundamental TE mode of a Si waveguide and, conversely, to control the polarization and set it to any arbitrary polarization state. In addition, the(More)
Mode division multiplexing is a promising technique that enables highly parallel and compact on-chip optical communications, but its scalability has been hampered by the crosstalk so far. By exploiting supermodes in closely packed waveguide arrays, low crosstalk between waveguides can be achieved when phase mismatch condition is met. This paper considers(More)
We report on an experimental prototype of a low-cost silicon photonic reconfigurable optical add/drop multiplexer (ROADM). The device is able to operate with up to 12 wavelength division multiplexing channels. In order to control the polarization of the multi-wavelength signal at the input of the device, an integrated polarization controller is investigated(More)
We demonstrate a method for the efficient modulation of optical wavelengths around 1550 nm in silicon waveguides. The amplitude of a propagating signal is mediated via control of the charge state of indium centers, rather than using free-carriers alone as in the plasma-dispersion effect. A 1×1 switch formed of an integrated p-i-n junction in an indium-doped(More)
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