Electromechanical tuning of double-membrane Photonic Crystal Cavities
PL spectra and peak shift obtained by applying a gradually increasing voltage are shown in Fig. 1b. We report up to 7 nm mode shift when the applied bias reaches 8.6 V. By further increasing the voltage we observe the well-known pull-in phenomenon: the cantilever collapses on the substrate because electrostatic forces win over elastic forces. We attribute the need for high voltages to fabrication issues and imperfections such as the complete erosion of the p-doped InGaAsP layer in the photonic crystal region during the sacrificial layer etching. Further process optimization should result in PCCs with Q factors>10'000, electromechanically tunable over >30 nm.
Photonic Integrated Circuits operating at the Single-Photon Level
We present an approach to the full integration of active and passive single-photon devices on a single chip. Single-photon sources coupled to waveguides are realized by embedding InAs quantum dots (QDs) in photonic crystal (PhC) cavities. In order to control the QD-cavity coupling, devices for the electrical control of both the exciton energy and the cavity resonant wavelength are demonstrated. A waveguide single-photon detector is obtained by patterning superconducting NbN nanowires on top of the ridge waveguides, resulting in high efficiency and low jitter. This set of technologies opens the way to fully integrated quantum photonic circuits for quantum information processing based on photonic qubits.
French film theory and criticism : a history/anthology, 1907-1939
These two volumes examine a significant but previously neglected moment in French cultural history: the emergence of French film theory and criticism before the essays of Andr Bazin. Richard Abel has devised an organizational scheme of six nearly symmetrical periods that serve to "bite into" the discursive flow of early French writing on the cinema. Each of the periods is discussed in a separate and extensive historical introduction, with convincing explications of the various concepts current at the time. In each instance, Abel goes on to provide a complementary anthology of selected texts in translation. Amounting to a portable archive, these anthologies make available a rich selection of nearly one hundred and fifty important texts, most of them never before published in English.