A spectroscopic laser sensor based on hybrid III-V/IV system-on-a-chip technology. The laser sensor is configured to either (i) be used with a fiber-optic probe connected to an intravenous/intra-arterial optical catheter for direct invasive blood analyte concentration level measurement or (ii) be used to measure blood analyte concentration level non-invasively through an optical interface attached, e.g., to the skin or fingernail bed of a human. The sensor includes a III-V gain-chip, e.g., an AlGaInAsSb/GaSb based gain-chip, and a photonic integrated circuit, with laser wavelength filtering, laser wavelength tuning, laser wavelength monitoring, laser signal monitoring and signal output sections realized on a chip by combining IV-based semiconductor substrates and flip-chip AlGa1-nAsSb/GaSb based photodetectors and embedded electronics for signal processing. Embodiments of the invention may be applied for real-time monitoring of critical blood analyte concentration levels such as lactates, urea, glucose, ammonia, albumin, etc.

Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

A disclosed semiconductor laser module includes a semiconductor laser device; a semiconductor optical amplifier configured to receive laser light emitted from the semiconductor laser device and amplify the laser light that has been received; and a first light receiving device that measures an intensity of a part of the laser light emitted from the semiconductor laser device, for monitoring a wavelength of the laser light, wherein the semiconductor optical amplifier is located rearward in relation to a light receiving surface of the first light receiving device along a propagation direction of the laser light emitted from the semiconductor device.

A light detection and ranging (LIDAR) device includes a substrate layer, a cladding layer, a waveguide, and an ohmic element. The cladding layer is disposed with the substrate layer. The waveguide runs through the cladding layer. The ohmic element runs through the cladding layer. The ohmic element is arranged to impart heat to the waveguide when an electrical current is driven through the ohmic element.

A thermally tunable laser includes: a substrate; a laser resonator, wherein the laser resonator includes a gain section, and wherein the laser resonator includes a tuning section; a heating arrangement; a heat sink arrangement for dissipating a heat flow from the laser resonator to the heat sink arrangement; and a hole arrangement for influencing the heat flow from the laser resonator to the heat sink arrangement, wherein the hole arrangement is arranged between the substrate and the heat sink arrangement, wherein one or more holes of the hole arrangement include at least one hole being arranged within a horizontal range of the tuning section, so that a thermal resistance between the tuning section and the heat sink arrangement is increased.

A direct modulation laser includes a distributed feedback type laser active region and an optical feedback region optically connected to one end of the laser active region in a waveguide direction. The direct modulation laser performs laser oscillation by using photon-photon resonance (PPR) that occurs depending on a frequency difference between a frequency of light generated (oscillated) in the laser active region and a frequency of an FP mode in the optical feedback region.

The present disclosure discloses a regulator circuit and regulator system for a tunable laser, the regulator circuit for the tunable laser includes a control module, a digital-to-analog conversion module and a semiconductor temperature regulation module; after the regulator circuit for the tunable laser is powered on, the control module is configured to send a control signal to the digital-to-analog conversion module, the digital-to-analog conversion module is configured to convert the control signal into an analog voltage signal and send the analog voltage signal to the semiconductor temperature regulation module, the semiconductor temperature regulation module is configured to cool or heat the tunable laser according to the received analog voltage signal.

A semiconductor optical device includes an SOI substrate having a waveguide of silicon, and at least one gain region of a group III-V compound semiconductor having an optical gain bonded to the SOI substrate. The waveguide has a bent portion and multiple linear portions extending linearly and connected to each other through the bent portion. The gain region is disposed on each of the multiple linear portions.

A method is for making a QCL having an InP spacer within a laser core, the QCL to provide a CW output in a high quality beam. The method may include selectively setting parameters for the QCL. The parameters may include a number of the InP spacer, a thickness for each InP spacer, a number of stages in the laser core, and a dopant concentration value in the laser core. The method may include forming the QCL based upon the parameters so that a figure of merit comprises a greatest value for a fundamental mode of operation for the QCL.

A laser apparatus includes: a laser unit including: a laser element unit including a phase adjusting portion configured to adjust an optical length of a laser resonator and enable frequency of laser light to be tuned; and a monitor unit configured to obtain a monitored value corresponding to the frequency of the laser light; a temperature controller configured to control temperature of the laser unit; and a control unit configured to execute: controlling the phase adjusting portion such that the monitored value is adjusted to a target monitored value corresponding to a target frequency set as the frequency of the laser light, while maintaining temperature set for the temperature controller constant; and controlling the temperature controller such that the frequency of the laser light is adjusted to the target frequency in a case where continuous fine adjustment control of the frequency of the laser light has been instructed.