Abstract: Detector assembly for downhole spectroscopy includes a near-infra-red quaternary photodiode that can operate at high temperatures without cooling it to the standard operation temperature range of the photodiode. High temperature operation of the photodiode right shifts the detector assembly's responsivity curve to include wavelengths of up to 2400-nm. The photodiode has manageable dark current at temperatures even at 200° C., and it can be packaged using high temperature construction. The photodiode is operated in photovoltaic mode at high temperatures but can be operated at photoconductive mode at lower temperatures. At least partial cooling can be provided above a predetermined temperature.

Abstract: A downhole fluid analysis tool has a housing and a flow passage for downhole fluid. A device disposed in the tool housing relative to the flow passage has a one or more sources, one or more sensing optics, one or more detectors, and control circuitry. The source generates an input signal. The sensing optic has a refractive index (RI) higher than crude oil and other expected constituents. A sensing surface of the optic optically coupled to the source interfaces with a downhole fluid. When the variable RI of the downhole fluid reaches a defined relationship to the optic's RI, the input signal interacting with the sensing surface experiences total internal reflection, and the reflected signal from the sensing surface remains in the sensing optic and reflects to a detector. The control circuitry monitors the detector's response and indicates gas break out if the response is above a threshold.

Abstract: Detector assembly for downhole spectroscopy includes a near-infra-red quaternary photodiode that can operate at high temperatures without cooling it to the standard operation temperature range of the photodiode. High temperature operation of the photodiode right shifts the detector assembly's responsivity curve to include wavelengths of up to 2400-nm. The photodiode has manageable dark current at temperatures even at 200° C., and it can be packaged using high temperature construction. The photodiode is operated in photovoltaic mode at high temperatures but can be operated at photoconductive mode at lower temperatures. At least partial cooling can be provided above a predetermined temperature.

Abstract: A downhole fluid analysis tool has a housing and a flow passage for downhole fluid. A device disposed in the tool housing relative to the flow passage has a one or more sources, one or more sensing optics, one or more detectors, and control circuitry. The source generates an input signal. The sensing optic has a refractive index (RI) higher than crude oil and other expected constituents. A sensing surface of the optic optically coupled to the source interfaces with a downhole fluid. When the variable RI of the downhole fluid reaches a defined relationship to the optic's RI, the input signal interacting with the sensing surface experiences total internal reflection, and the reflected signal from the sensing surface remains in the sensing optic and reflects to a detector. The control circuitry monitors the detector's response and indicates gas break out if the response is above a threshold.

Abstract: An electro-optical interface with a package base having an electrical connection configuration suitable for connecting to a source of electrical signals. A semiconductor optical signal source is provided mounted to the base and having a second or higher order grating in the cavity. The signal source is operatively connected to the package base whereby the electronic signals may be converted into optical signals. A waveguide is positioned adjacent to the signal source to couple the optical signal to the waveguide. The cavity is sized, shaped and positioned so that a radiation field for the cavity is not a mode discrimination mechanism wherein any back reflections into the cavity will affect a coupling coefficient to the radiation field without significantly adversely affecting the output signal quality.

Abstract: A surface emitting semiconductor laser is shown having a semiconductor laser structure defining an intrinsic cavity having an active layer, opposed cladding layers contiguous to said active layer, a substrate and electrodes by which current can be injected into said semiconductor laser structure to cause said laser structure to emit an output signal in the form of at least a surface emission. The intrinsic cavity is configured to have a dominant mode on a longer wavelength side of a stop band. A structure such as a buried heterostructure for laterally confining an optical mode is included. A second order distributed diffraction grating is associated with the intrinsic cavity, the diffraction grating having a plurality of grating elements having periodically alternating optical properties when said current is injected into said laser structure.

Abstract: An electro-optical interface with a package base having an electrical connection configuration suitable for connecting to a source of electrical signals. A semiconductor optical signal source is provided mounted to the base and having a second or higher order grating in the cavity. The signal source is operatively connected to the package base whereby the electronic signals may be converted into optical signals. A waveguide is positioned adjacent to the signal source to couple the optical signal to the waveguide. The cavity is sized, shaped and positioned so that a radiation field for the cavity is not a mode discrimination mechanism wherein any back reflections into the cavity will affect a coupling coefficient to the radiation field without significantly adversely affecting the output signal quality.

Abstract: A gate for an optical signal having a waveguide which can be coupled to a source of optical signals, where the waveguide comprises a cladding surrounding a core. A gate material is provided which is sized, shaped and positioned outside of the core such that an optical signal passing along the core interacts with said gate material. A source of power stimulates the gate material and the power source is switchable between on and off. The optical signal is attenuated by interacting with said gate material when the power is off and amplified by interacting with said gate material when the power is on. In one embodiment the gate is packaged into a planar light circuit having a multiplexer/demultiplexer at either end and a gate region including a plurality of gates. A method of forming such a device is also shown.

Abstract: An amplifier for optical signals is disclosed. The amplifier includes a source of optical pump power and a containment body for substantially containing the pump power at a predetermined power intensity. At least one guided signal path passes through the containment body, the signal path being capable of carrying at least one optical signal component. The source of optical pump power is coupled to the containment body. In one embodiment the containment body is a transparent material surrounded by a material having a lower index of a fraction. Pump power is contained within the containment body by means of total internal reflection (TIR). In another embodiment the containment body is formed from a metallic reflective material which surrounds the guided signal paths passing through the containment body.