Abstract: A method for detecting and identifying a remote gas, the method comprising the steps of: receiving a light wave associated with the remote gas; coupling the light wave into a single mode fibre; transmitting the light wave via the single mode fibre into a filter comprising a fibre-based tunable cavity; modulating the cavity length of the filter transmission window to cause a detected modulated signal that is proportional to the spectral feature; and processing the signal using a lock-in amplifier capable of low-pass filtering and out-of-frequency noise rejection.

Abstract: An integrated optical sensor enables the detection and identification of one or more remote gases using a transmission filter that matches specific absorption features of a remote gas and is detected using a single photodetection element. The sensor comprises an integrated optical component that is characterized by its transmission spectrum which corresponds to absorption or emission features of a target gas over a defined spectral bandpass, and the ability to have a reversibly tunable transmission spectrum. The change in the optical power output from the sensor as the transmission spectrum is tuned is proportional to the optical depth of the target gas absorption lines when viewed with a background light source. The optical power output from the integrated optical component is therefore related to the absorption spectrum of the input light Physical properties of the sensor are tailored to produce a quasi-periodic transmission spectrum that results in a stronger signal contrast for a specific gas.

Abstract: An integrated optical sensor enables the detection and identification of one or more remote gases using a transmission filter that matches specific absorption features of a remote gas and is detected using a single photodetection element. The sensor comprises an integrated optical component that is characterized by its transmission spectrum which corresponds to absorption or emission features of a target gas over a defined spectral bandpass, and the ability to have a reversibly tunable transmission spectrum. The change in the optical power output from the sensor as the transmission spectrum is tuned is proportional to the optical depth of the target gas absorption lines when viewed with a background light source. The optical power output from the integrated optical component is therefore related to the absorption spectrum of the input light Physical properties of the sensor are tailored to produce a quasi-periodic transmission spectrum that results in a stronger signal contrast for a specific gas.

Abstract: A method of fabricating a solid state radiation detector method includes mechanically lapping and polishing the first and the second surfaces of a semiconductor wafer using a plurality of lapping and polishing steps. The method also includes growing passivation oxide layers by use of oxygen plasma on the top of the polished first and second surfaces in order to passivate the semiconductor wafer. Anode contacts are deposited and patterned on top of the first passivation oxide layer, which is on top of the first surface. Cathode contacts, which are either monolithic or patterned, are deposited on top of the second passivation oxide layer, which is on the second surface. Aluminum nitride encapsulation layer can be deposited over the anode contacts and patterned to encapsulate the first passivation oxide layer, while physically exposing a center portion of each anode contact to electrically connect the anode contacts.

Abstract: A method of fabricating a solid state radiation detector method includes mechanically lapping and polishing the first and the second surfaces of a semiconductor wafer using a plurality of lapping and polishing steps. The method also includes growing passivation oxide layers by use of oxygen plasma on the top of the polished first and second surfaces in order to passivate the semiconductor wafer. Anode contacts are deposited and patterned on top of the first passivation oxide layer, which is on top of the first surface. Cathode contacts, which are either monolithic or patterned, are deposited on top of the second passivation oxide layer, which is on the second surface. Aluminum nitride encapsulation layer can be deposited over the anode contacts and patterned to encapsulate the first passivation oxide layer, while physically exposing a center portion of each anode contact to electrically connect the anode contacts.

Abstract: A method of fabricating a solid state radiation detector method includes mechanically lapping and polishing the first and the second surfaces of a semiconductor wafer using a plurality of lapping and polishing steps. The method also includes growing passivation oxide layers by use of oxygen plasma on the top of the polished first and second surfaces in order to passivate the semiconductor wafer. Anode contacts are deposited and patterned on top of the first passivation oxide layer, which is on top of the first surface. Cathode contacts, which are either monolithic or patterned, are deposited on top of the second passivation oxide layer, which is on the second surface. Aluminum nitride encapsulation layer can be deposited over the anode contacts and patterned to encapsulate the first passivation oxide layer, while physically exposing a center portion of each anode contact to electrically connect the anode contacts.

Abstract: A method of fabricating a solid state radiation detector method includes mechanically lapping and polishing the first and the second surfaces of a semiconductor wafer using a plurality of lapping and polishing steps. The method also includes growing passivation oxide layers by use of oxygen plasma on the top of the polished first and second surfaces in order to passivate the semiconductor wafer. Anode contacts are deposited and patterned on top of the first passivation oxide layer, which is on top of the first surface. Cathode contacts, which are either monolithic or patterned, are deposited on top of the second passivation oxide layer, which is on the second surface. Aluminum nitride encapsulation layer can be deposited over the anode contacts and patterned to encapsulate the first passivation oxide layer, while physically exposing a center portion of each anode contact to electrically connect the anode contacts.

Abstract: A technique for high sensitivity evanescent field molecular sensing employs a detection scheme that simultaneously couples a polarized beam to a single mode of a waveguide, and couples the polarized beam out of the waveguide to specularly reflect the beam by the same grating. Strong interaction with the single (preferably TM) mode is provided by using a silicon on insulator (SOI) wafer having a waveguide thickness chosen between 10-400 nm so that the majority of the mode field strength spans the evanescent field. Well known, robust techniques for producing a grating on the waveguide are provided. Interrogation from a backside of the SOI wafer is taught.

Abstract: A waveguide cores consisting of a subwavelength grating permits transmission of light without diffraction in a discontinuous manner, wherein the energy is provided by field hopping between subwavelength material segments of higher index. The use of alternating segments permits design of waveguides having desired effective index, mode confinement factor, birefringence, polarization mode or mode dispersions, polarization dependent loss, thermal sensitivity, or nonlinear optical coefficient. An optical system comprises a waveguide having such a core, clad on at least one side, extending between two ends, and wavelength-limiting optical components in optical communication with the ends.

Abstract: A waveguide cores consisting of a subwavelength grating permits transmission of light without diffraction in a discontinuous manner, wherein the energy is provided by field hopping between subwavelength material segments of higher index. The use of alternating segments permits design of waveguides having desired effective index, mode confinement factor, birefringence, polarization mode or mode dispersions, polarization dependent loss, thermal sensitivity, or nonlinear optical coefficient. An optical system comprises a waveguide having such a core, clad on at least one side, extending between two ends, and wavelength-limiting optical components in optical communication with the ends.

Abstract: A technique for high sensitivity evanescent field molecular sensing employs a detection scheme that simultaneously couples a polarized beam to a single mode of a waveguide, and couples the polarized beam out of the waveguide to specularly reflect the beam by the same grating. Strong interaction with the single (preferably TM) mode is provided by using a silicon on insulator (SOI) wafer having a waveguide thickness chosen between 10-400 nm so that the majority of the mode field strength spans the evanescent field. Well known, robust techniques for producing a grating on the waveguide are provided. Interrogation from a backside of the SOI wafer is taught.

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: An interface device for performing mode transformation in optical waveguides includes an optical waveguide core for propagating light of a particular wavelength or a plurality of wavelengths. The optical waveguide core terminates in a subwavelength grating configured to change the propagation mode of the light. The subwavelength grating has a pitch sufficiently less than the wavelength of the light to frustrate diffraction. The device can thus serve as an optical coupler between different propagating media, or as an anti-reflective or high reflectivity device.

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 interface device for performing mode transformation in optical waveguides includes an optical waveguide core for propagating light of a particular wavelength or a plurality of wavelengths. The optical waveguide core terminates in a subwavelength grating configured to change the propagation mode of the light. The subwavelength grating has a pitch sufficiently less than the wavelength of the light to frustrate diffraction. The device can thus serve as an optical coupler between different propagating media, or as an anti-reflective or high reflectivity device.

Abstract: An interface device for performing mode transformation in optical waveguides includes an optical waveguide core for propagating light of a particular wavelength. The optical waveguide core terminates in a subwavelength grating configured to change the propagation mode of the light. The subwavelength grating has a pitch sufficiently less than the wavelength of the light to frustrate diffraction. The device can thus serve as an optical coupler between different propagating media, or as an anti-reflective or high reflectivity device.