Optical switch

About: Optical switch is a research topic. Over the lifetime, 28538 publications have been published within this topic receiving 351176 citations.

Overlap integral factors in integrated optic modulators and switches

Abstract: Coplanar strip and complementary coplanar strip electrodes are often used in integrated optical switches and modulators using the optical directional coupler. The field analysis of these electrodes is performed to determine the optimum overlap integral between the optical field and the modulating electromagnetic field. The optimal placement of the electrodes with respect to the optical channel waveguides is presented as a function of electrode width and spacing. >

Automated electrophoresis and fluorescence detection apparatus and method

Abstract: Improved detection methods and apparatus which may be used individually or in various combinations enhance the ability of the electrophoresis apparatus to detect fluorophore-labeled materials in short periods of time. One such apparatus comprises a housing adapted to receive an electrophoresis gel holder; an excitation source of electromagnetic radiation having a frequency effective to induce emission of electromagnetic radiation from the fluorophore; a plurality of optical fibers for delivering electromagnetic radiation from the excitation source to a linear array of excitation/detection sites on the gel holder, optical switching means for sequentially directing electromagnetic radiation into one of several pre-defined groups of the optical fibers; detection means such as a photomultiplier tube, or an array of photomultiplier tubes for detecting emission from the fluorophore induced by a radiation from the excitation source; and means for correlating a detected emission with the switching of the excitation electromagnetic radiation such that a given emission may be linked with the excitation/detection site being irradiated. For example, the optical switching means may alternate between directing radiation from the source into every other optical fiber, or may provide radiation in rotation to every third or fourth fiber. Alternatively, a spot array generation grating can be used for dividing an incident beam of coherent radiation into an array of excitation beamlets and directing each excitation beamlet to an excitation/detection site on the electrophoresis gel. Light emitting diode disposed to deliver excitation energy to an array of excitation/detection sites may also be used. This latter form of the apparatus is particularly advantageous due to the low costs of light emitting diodes (LEDs) compared to coherent light sources (e.g. lasers).

Polymeric optical waveguide switch using the thermooptic effect

Abstract: An all-polymeric optical waveguide switch which uses total internal reflection from a thermally induced index barrier is discussed. Very large effective index changes Delta N=2*10/sup -2/ were found in the polymeric waveguide. The temperature under the evaporated stripe heater was measured from the change in its resistance. The effective index change due to the temperature increase agrees well with values calculated from the deflection angles. The operation of the switch is, apart from a small waveguide dispersion effect, polarization-insensitive. Switching times of about 10 ms were measured. It should be possible to reduce them to a few milliseconds in optimized thermal designs and with regulated power dissipation in the heater. >

Integrated wavelength-selective optical MEMS switching using ring resonator filters

Abstract: An integrated optical microelectromechanical system (MEMS) switch that provides wavelength selectivity is described. The switching mechanism is based on moving a MEMS actuated optically absorbing membrane into the evanescent field of a high-index-contrast optical ring resonator. By controlling the loss, and thus, the cavity quality factor, the resonant wavelength is switched between the drop and through ports.

Nanophotonic switch using ZnO nanorod double-quantum-well structures

Abstract: The authors report on time-resolved near-field spectroscopy of ZnO∕ZnMgO nanorod double-quantum-well structures (DQWs) for a nanometer-scale photonic device. They observed nutation of the population between the resonantly coupled exciton states of DQWs. Furthermore, they demonstrated switching dynamics by controlling the exciton excitation in the dipole-inactive state via an optical near field. The results of time-resolved near-field spectroscopy of isolated DQWs described here are a promising step toward designing a nanometer-scale photonic switch and related devices.