Abstract: Methods and devices related to a sensor element for use in the detection and monitoring of molecular interactions. The sensor element uses a silicon-on-insulator wafer optically coupled to a silicon prism. The wafer has a thin silicon film top layer, a silicon substrate layer, and a buried silicon dioxide layer sandwiched between the silicon film and substrate layers. The wafer is coupled to the prism on the wafer's substrate side while the interactions to be monitored are placed on the wafer's silicon film side. An incident beam is directed at the prism and the incident angle is adjusted until the beam optically couples to the silicon film's optical waveguide mode. When this occurs, a decrease in the intensity of the reflected beam can be detected. The molecular interactions affect the phase velocity or wave vector of the propagating mode. Similarly, instead of measuring the incident angle at which optical coupling occurs, the phase of the reflected beam may be measured.

Abstract: Methods and devices relating to a sensor for use in detecting and monitoring molecular interactions. A silicon waveguide sensing element is provided along with a layer of silicon. A silicon oxide layer is also provided between the waveguide element and the layer of silicon. The sensing element is adjacent to an aqueous solution in which the molecular interactions are occurring. A light beam travelling in the silicon waveguide creates an evanescent optical field on the surface of the sensing element adjacent to the boundary between the sensing element and the aqueous medium. Molecular interactions occurring on this surface affect the intensity or the phase of the light beam travelling through the waveguide by changing the effective refractive index of the medium. By measuring the effect on the intensity, phase, or speed of the light beam, the molecular interactions can be detected and monitored in real time.

Abstract: Methods and devices relating to sensors and sensor blocks for use in detecting and monitoring molecular interactions. A silicon waveguide sensing element is provided along with a layer of silicon. A silicon oxide layer is also provided between the waveguide element and the layer of silicon. The sensing element is adjacent to an aqueous solution in which the molecular interactions are occurring. A light beam travelling in the silicon waveguide creates an evanescent optical field on the surface of the sensing element adjacent to the boundary between the sensing element and the aqueous medium. Molecular interactions occurring on this surface affect the intensity or the phase of the light beam travelling through the waveguide by changing the effective refractive index of the medium. By measuring the effect on the intensity, phase, or speed of the light beam, the molecular interactions can be detected and monitored in real time. Various configurations using this sensor technology is also disclosed.

Abstract: Methods and devices relating to a sensor for use in detecting and monitoring molecular interactions. A silicon waveguide sensing element is provided along with a layer of silicon. A silicon oxide layer is also provided between the waveguide element and the layer of silicon. The sensing element is adjacent to an aqueous solution in which the molecular interactions are occurring. A light beam travelling in the silicon waveguide creates an evanescent optical field on the surface of the sensing element adjacent to the boundary between the sensing element and the aqueous medium. Molecular interactions occurring on this surface affect the intensity or the phase of the light beam travelling through the waveguide by changing the effective refractive index of the medium. By measuring the effect on the intensity, phase, or speed of the light beam, the molecular interactions can be detected and monitored in real time.

Abstract: An Echelle grating has alternate first (1a) and second (1b) sets of facets (1). The first set of facets (1a) is operative to reflect incident light (4) for diffraction and the second set of facets (1b) extends between adjacent facets of the first set (1a). Only the first set of facets (1a) is metallized to enhance reflection. The second set of facets (1b) is left unmetallized. This configuration reduces polarization dependent loss (PDL).

Abstract: An optical performance monitor for measuring the performance of optical networks has an echelle grating for demultiplexing an input beam into a plurality of wavelengths that are focused onto an array of divided output waveguides. Each divided output waveguide is positioned to receive a corresponding demultiplexed wavelength from the echelle grating or other waveguide multiplexer device. The divided output waveguides laterally separate the corresponding demultiplexed wavelength into a first and second portions. A detector array is positioned to receive the respective portions of the demultiplexed wavelengths and by comparing their relative intensity it is possible to detect any drift in the nominal wavelengths of the channels.

Abstract: An Echelle grating has alternate first (1a) and second (1b) sets of facets (1). The first set of facets (1a) is operative to reflect incident light (4) for diffraction and the second set of facets (1b) extends between adjacent facets of the first set (1a). Only the first set of facets (1a) is metallized to enhance reflection. The second set of facets (1b) is left unmetallized. This configuration reduces polarization dependent loss (PDL).

Abstract: A method is desribed for controlling the pass band of an optical device wherein a phase mask is introduced to modify the shaped of an image produced by the photonic device.

Abstract: The method consists of creating a compensating region within the slab waveguide region, with effective TE and TM mode refractive indices of the compensating region higher than those of the original slab waveguide. Such change in refractive indices is achieved by deposition of an over-layer on the compensating region.

Abstract: Disclosed is an optical double pass equalizer for equalizing a wavelength division multiplexed (WDM) signal. The equalizer comprises a multiplexer/demultiplexer and multiple variable optical attenuators (VOAs) integrated on a single monolithic chip. The WDM signal is demultiplexed into individual wavelength channels by the multiplexer/demultiplexer and each wavelength channel is equalized by a corresponding VOA. The equalized wavelength channels are then multiplexed into an equalized WDM signal by the multiplexer/demultiplexer. This provides several advantages, including a reduction in required assembly and assembly cost, as well as an improved dynamic range in attenuation level or alternatively a reduction in power consumption for a fix attenuation level compared to a single pass VOA unit.

Abstract: A planar waveguide grating device has a slab waveguide defining an input channel and a plurality of output channels. An echelle grating has a multitude of facets, each of the facets being blazed with respect to a preselected output channel. Each facet has an elliptical curvature so as to be astigmatic with respect to the input channel and the preselected output channel. The echelle grating is preferably based on a Rowland circle design. The astigmatic design of the facets reduces aberrations at high orders.

Abstract: In a digital optical switch, an input waveguide and two output waveguides form a Y-shaped splitter or switch. Electrodes are positioned on each output waveguide at the junction with the input waveguide. The electrodes extend as narrow strips across the waveguides. The inner edges of the electrodes are curved to form a smooth continuation profile to the signal paths to reduce losses.

Abstract: A planar waveguide grating device has a slab waveguide defining an input channel and a plurality of output channels. An echelle grating has a multitude of facets, each of the facets being blazed with respect to a preselected output channel. Each facet has an elliptical curvature so as to be astigmatic with respect to the input channel and the preselected output channel. The echelle grating is preferably based on a Rowland circle design. The astigmatic design of the facets reduces aberrations at high orders.

Abstract: A method is disclosed for polarization birefringence compensation in a photonic device with a slab waveguide having a core. A compensator region is formed in the slab waveguide to minimize the wavelength shift between light of different polarizations. A thin capping layer, typically of silicon nitride, having a higher refractive index than the core, is formed on the compensator region to increase the birefringence contrast between the compensator region and the planar waveguide.

Abstract: A method is disclosed for polarization birefringence compensation in a photonic device with a slab waveguide having a core. A compensator region is formed in the slab waveguide to minimize the wavelength shift between light of different polarizations. A thin capping layer, typically of silicon nitride, having a higher refractive index than the core is formed on the compensator region to increase the birefringence contrast between the compensator region and the planar waveguide.

Abstract: An optical performance monitor for measuring the performance of optical networks has an echelle grating for demultiplexing an input beam into a plurality of wavelengths that are focused onto an array of divided output waveguides. Each divided output waveguide is positioned to receive a corresponding demultiplexed wavelength from the echelle grating or other waveguide multiplexer device. The divided output waveguides laterally separate the corresponding demultiplexed wavelength into a first and second portions. A detector array is positioned to receive the respective portions of the demultiplexed wavelengths and by comparing their relative intensity it is possible to detect any drift in the nominal wavelengths of the channels.

Abstract: In a digital optical switch, an input waveguide and two output waveguides form a Y-shaped splitter or switch. Electrodes are positioned on each output waveguide at the junction with the input waveguide. The electrodes extend as narrow strips across the waveguides. The inner edges of the electrodes are curved to form a smooth continuation profile to the signal paths to reduce losses.

Abstract: In a digital optical switch, an input waveguide and two output waveguides form a Y-shaped splitter or switch. Electrodes are positioned on each output waveguide at the junction with the input waveguide. The electrodes extend as narrow strips across the waveguides. The inner edges of the electrodes are curved to form a smooth continuation profile to the signal paths to reduce losses.

Abstract: A planar waveguide optical device whose wavelengths are stabilized by temperature, has an input channel, a series of output data channels, and a dispersive element, such as a diffraction grating or phase array, for directing component wavelengths of incoming light into the respective output data channels. A pair of monitor channels have a separation less than, and a width greater than, the data channels. A differential feedback arrangement controls the temperature of the demultiplexer according a differential signal received from the pair of monitor channels.

Abstract: A method of manufacturing a honeycomb structure of thermostructural composite material comprising a fiber reinforcing fabric densified by a matrix, the fibers of the reinforcing fabric being of a material selected from carbon and ceramics, as is the matrix, the method comprising the following steps:making a three-dimensional fiber fabric by means of superposed two-dimensional plies that are bonded together by means of fibers passing through the plies;making slit-shaped cuts in a staggered configuration through the plies, and through the entire thickness of the fabric;stretching the cut fabric in a direction that is not parallel to the cuts but that is parallel to the plies so as to form cells whose walls are constituted by the lips of the cuts; andwhile the cut texture is held in the stretched state, densifying it using the matrix-constituting material to obtain a rigid honeycomb structure of thermostructural material.