Abstract: Systems and methods for measuring flow velocity of a fluid mixture in a lateral section of an oil/gas/water well with a dual beam laser doppler velocimetry (LVD) based flow sensor are presented. According to one aspect, the flow velocity is measured by tracking movement of particles and/or features in the fluid mixture while traversing an interference pattern generated by the intersection of two separate coherent beams that are perpendicular to a direction of the flow. Flow velocity is derived based on a time it takes the particles to traverse consecutive fringes of the interference pattern as indicated by intensity peaks detected at the photodetector. The LDV-based flow sensor may be rotatable to measure flow velocities at different angular positions of a pipe in a lateral section of an oil well, rotation provided by rotation of an element of a mobile vessel to which the flow sensor is rigidly coupled.

Abstract: Disclosed herein is a spectroscopy device incorporating a mid-infrared laser. In one particular embodiment a spectroscopy device is provided including: a substrate; a single mode laser positioned on the substrate; a single mode detector positioned opposite to the single mode laser on the substrate. A gap is formed between the single mode laser and the single mode detector and a substance is positioned in the gap. The single mode laser is configured to output a tunable narrow wavelength of radiation towards the detector and when the single mode laser outputs a wavelength of radiation overlapping one of the substance's rotational-vibrational energy levels, the substance at least partially absorbs the radiation. The single mode detector is configured to measure the amount of narrow wavelength radiation that is not absorbed by the substance between the single mode detector and the single mode laser.

Abstract: Systems and methods for measuring flow velocity of a fluid mixture in a lateral section of an oil/gas well are presented. The flow velocity is measured by tracking movement of particles and/or features in the fluid mixture via visible and/or infrared imaging sensors of a camera-based flow sensor. According to another aspect, the imaging sensors detect back-reflected light by the particles and/or features, the light emitted by illuminators in the visible and/or infrared spectrum. According to yet another aspect, the particles are quantum dot illuminators injected into the fluid mixture, the flow velocity based on a time-of-flight of the quantum dots. The camera-based flow sensor may be rotatable to measure flow velocities at different angular positions of a pipe, rotation provided by rotation of an element of a mobile vessel to which the flow sensor is rigidly coupled.

Abstract: Single-mode distributed-feedback (DFB) lasers including single mode DFB waveguides with tapered grating structures are provided herein. Tapered grating structures provide for single mode DFB waveguides with predictable single mode operation. Uniform grating structures may provide for single mode operation, however DFB waveguides implementing uniform grating structures may operate at one of two single modes. Advantageously, DFB waveguides with tapered gratings operate with a spectrally narrow single mode at the same predictable single mode for all DFB waveguides with substantially identical specifications. Such predictability may lead to increased yield during manufacture of DFB waveguides with tapered gratings.

Abstract: Single-mode distributed-feedback (DFB) lasers including single mode DFB waveguides with tapered grating structures are provided herein. Tapered grating structures provide for single mode DFB waveguides with predictable single mode operation. Uniform grating structures may provide for single mode operation, however DFB waveguides implementing uniform grating structures may operate at one of two single modes. Advantageously, DFB waveguides with tapered gratings operate with a spectrally narrow single mode at the same predictable single mode for all DFB waveguides with substantially identical specifications. Such predictability may lead to increased yield during manufacture of DFB waveguides with tapered gratings.