Abstract: A method and a system for providing a low absorption Bragg grating along a grating region of an optical fiber are presented. The Bragg grating is written along the grating region by multiphoton absorption of ultrafast light pulses impinged on this grating region through a polymer coating of the optical fiber. The Bragg grating is then photobleached by propagating a photobleaching light beam along the optical fiber. The photobleaching light beam has optical parameters selected to reduce defects in the grating region induced by the writing of the Bragg grating in a substantially non-thermal regime.

Abstract: The present disclosure relates to analytical testing devices comprising microfluidics and methods for performing an assay on a fluid sample received within the microfluidics, and in particular, to mitigating drift of fluid samples over a sensor by incorporating a bypass channel into the microfluidics. For example, a test cartridge device is provided that includes a fluid sample entry port and holding chamber connected to a bifurcation junction of a sensor channel and a bypass channel. The sensor channel includes an upstream region and a downstream region, and an analyte sensor is in the upstream region. As a cross-sectional area of the bypass channel is greater than the cross-sectional area of the downstream region of the sensor channel, the bypass channel is a preferred path for excess sample flow and pressure, and thus sample drift above the analyte sensor is mitigated.

Abstract: A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head.

Abstract: In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam and a seed-laser focusing lens configured to focus the seed-laser beam. The laser system also includes a semiconductor optical amplifier (SOA) that includes a front facet, a back facet, and a waveguide extending from the front facet to the back facet. The SOA is configured to: receive, at the front facet, light from the focused seed-laser beam; amplify the received light as the received light propagates along the SOA waveguide from the front facet to the back facet; and emit, from the back facet, an amplified free-space beam that includes the amplified received light. The laser system further includes a mounting platform, where one or more of the seed laser diode, the seed-laser focusing lens, and the SOA are mechanically attached to the mounting platform.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light. The lidar system also includes multiple optical links and multiple sensor heads. Each optical link couples the light source to a corresponding sensor head, and each optical link is configured to convey at least a portion of the emitted pulses of light from the light source to the corresponding sensor head. Each sensor head includes a scanner configured to scan pulses of light across a field of regard of the sensor head, where the scanned pulses of light include the portion of the emitted pulses of light conveyed from the light source to the sensor head by the corresponding optical link. Each sensor head also includes a receiver configured to detect at least a portion of the scanned pulses of light scattered or reflected by a target located downrange from the sensor head.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan at least a portion of the emitted pulses of light across a field of regard. The lidar system also includes a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system.

Abstract: The present disclosure relates to analytical testing devices comprising microfluidics and methods for performing an assay on a fluid sample received within the microfluidics, and in particular, to mitigating drift of fluid samples over a sensor by incorporating a bypass channel into the microfluidics. For example, a test cartridge device is provided that includes a fluid sample entry port and holding chamber connected to a bifurcation junction of a sensor channel and a bypass channel. The sensor channel includes an upstream region and a downstream region, and an analyte sensor is in the upstream region. As a cross-sectional area of the bypass channel is greater than the cross-sectional area of the downstream region of the sensor channel, the bypass channel is a preferred path for excess sample flow and pressure, and thus sample drift above the analyte sensor is mitigated.

Abstract: In one embodiment, a laser system includes a seed laser configured to produce optical seed pulses. The laser system also includes a first fiber-optic amplifier configured to amplify the seed pulses by a first amplifier gain to produce a first-amplifier output that includes amplified seed pulses and amplified spontaneous emission (ASE). The laser system further includes a first optical filter configured to remove from the first-amplifier output an amount of the ASE. The laser system also includes a second fiber-optic amplifier configured to receive the amplified seed pulses from the first optical filter and amplify the received pulses by a second amplifier gain to produce output pulses. The output pulses have output-pulse characteristics that include: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%.

Abstract: In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam and a seed-laser focusing lens configured to focus the seed-laser beam. The laser system also includes a semiconductor optical amplifier (SOA) that includes a front facet, a back facet, and a waveguide extending from the front facet to the back facet. The SOA is configured to: receive, at the front facet, light from the focused seed-laser beam; amplify the received light as the received light propagates along the SOA waveguide from the front facet to the back facet; and emit, from the back facet, an amplified free-space beam that includes the amplified received light. The laser system further includes a mounting platform, where one or more of the seed laser diode, the seed-laser focusing lens, and the SOA are mechanically attached to the mounting platform.

Abstract: In one embodiment, a fiber-optic amplifier includes an optical gain fiber configured to amplify input light received from a seed laser. The optical gain fiber includes a first gain section configured to: receive the seed-laser input light and co-propagating pump light; and amplify the seed-laser input light as it propagates along the first gain section. The seed-laser input light and the co-propagating pump light propagate along the first gain section in a same direction. The optical gain fiber also includes a second gain section configured to: receive the amplified input light from the first gain section; receive counter-propagating pump light; and further amplify the amplified input light as it propagates along the second gain section. The amplified input light and the counter-propagating pump light propagate along the second gain section in opposite directions. The fiber-optic amplifier also includes a first pump laser diode and a second pump laser diode.

Abstract: In one embodiment, a lidar system includes a light source configured to emit a ranging pulse of light that is directed into a field of regard of the lidar system. The lidar system also includes a fiber-optic splitter configured to split off a portion of the ranging pulse of light to produce a trigger pulse of light that is directed to a receiver of the lidar system. The receiver is configured to detect, at a first time, at least a portion of the trigger pulse of light; and detect, at a second time subsequent to the first time, a portion of the ranging pulse of light scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target based at least in part on the first time and the second time.

Abstract: In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam. The laser system also includes a pump laser diode configured to produce a free-space pump-laser beam. The laser system further includes an optical-beam combiner configured to combine the seed-laser and pump-laser beams into a combined free-space beam and a focusing lens configured to focus the combined beam. The laser system also includes an optical gain fiber that includes an input end configured to receive the focused beam. The laser system also includes a mounting platform, where one or more of the optical-beam combiner, the focusing lens, and the input end of the gain fiber are mechanically attached to the platform.

Abstract: In one embodiment, an optical amplifier includes a first pump laser diode and a second pump laser diode. The first pump laser diode is configured to produce pump light that includes a first amount of optical power at a first wavelength, and the second pump laser diode is configured to produce pump light that includes a second amount of optical power at a second wavelength different from the first wavelength. The optical amplifier also includes an optical gain fiber configured to receive the pump light from the first and second pump laser diodes and provide optical gain for an optical signal propagating through the optical gain fiber. The optical amplifier further includes a controller configured to adjust the first amount of optical power produced by the first pump laser diode and the second amount of optical power produced by the second pump laser diode.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan at least a portion of the emitted pulses of light across a field of regard. The lidar system also includes a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system.

Abstract: A lidar system with a pulsed laser diode to produce a plurality of optical seed pulses of light at one or more operating wavelengths between approximately 1400 nm and approximately 1600 nm. The lidar system may also include one or more optical amplifiers to amplify the optical seed pulses to produce a plurality of output optical pulses. Each optical amplifier may produce an amount of amplified spontaneous emission (ASE), and the output optical pulses may have characteristics comprising: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%. The lidar system may also include one or more optical filters to attenuate the ASE and a receiver to detect at least a portion of the output optical pulses scattered by a target located a distance.

Abstract: In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam and a seed-laser lens configured to collimate the seed-laser beam. The laser system also includes a pump laser diode configured to produce a free-space pump-laser beam and a pump-laser lens configured to collimate the pump-laser beam. The laser system further includes an optical-beam combiner configured to combine the collimated seed-laser and pump-laser beams into a combined free-space beam and a focusing lens configured to focus the combined beam. The laser system also includes an optical gain fiber that includes an input end configured to receive the focused beam. The laser system also includes a mounting platform, where one or more of the seed laser, the seed-laser lens, the pump laser, the pump-laser lens, the combiner, the focusing lens, and the input end of the gain fiber are mechanically attached to the platform.

Abstract: A lidar system with a pulsed laser diode to produce a plurality of optical seed pulses of light at one or more operating wavelengths between approximately 1400 nm and approximately 1600 nm. The lidar system may also include one or more optical amplifiers to amplify the optical seed pulses to produce a plurality of output optical pulses. Each optical amplifier may produce an amount of amplified spontaneous emission (ASE), and the output optical pulses may have characteristics comprising: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%. The lidar system may also include one or more optical filters to attenuate the ASE and a receiver to detect at least a portion of the output optical pulses scattered by a target located a distance.

Abstract: A lidar system with a light source to emit a pulse of light and a receiver to detect a return pulse of light. The receiver can include a first channel to receive a first portion of the return pulse and produce a first digital output signal, and a second channel to receive a second portion of the return pulse and produce a second digital output signal. The receiver can include a logic circuit to produce an output electrical-edge signal in response to receiving the digital output signals. The receiver can also include a time-to-digital converter to determine a time interval based on an emission time of the pulse of light and based on the electrical-edge signal. The lidar system can also include a processor to determine a distance to a target based at least in part on the time interval.

Abstract: A lidar system with a light source to emit a pulse of light and a receiver to detect a return pulse of light. The receiver can include a first channel to receive a first portion of the return pulse and produce a first digital output signal, and a second channel to receive a second portion of the return pulse and produce a second digital output signal. The receiver can include a logic circuit to produce an output electrical-edge signal in response to receiving the digital output signals. The receiver can also include a time-to-digital converter to determine a time interval based on an emission time of the pulse of light and based on the electrical-edge signal. The lidar system can also include a processor to determine a distance to a target based at least in part on the time interval.

Abstract: A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head.