A nitride semiconductor laser element includes a stacked structure and a dielectric multilayer film, The dielectric multilayer film includes a first dielectric film, a second dielectric film, and a third dielectric film in the stated order. The nitride semiconductor laser element satisfies the following expressions:

[00001]$.Math.\mathrm{nk}\times \mathrm{dk}+\mathrm{ni}\times \mathrm{di}+\mathrm{nj}\times \mathrm{dj}=m1\times \frac{\lambda }{4}\pm \frac{\lambda }{16};$$\mathrm{nj}\times \mathrm{dj}=m2\times \lambda /4\pm \lambda /16;\mathrm{and}$$\frac{3\lambda }{16}\leqq .Math.\mathrm{nk}\times \mathrm{dk}\leqq \frac{5\lambda }{16}.$

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 semiconductor laser machine includes a semiconductor laser element including a first end face that emits a laser beam and a second end face that is opposite the first end face; a heat sink; and a sub-mount securing the semiconductor laser element to the heat sink. The sub-mount includes a substrate that serves as a thermal stress reliever, a solder layer joined to the semiconductor laser element, and a junction layer formed between the substrate and the solder layer. Compared with the semiconductor laser element, the substrate is extended in a rearward direction that is from the first end face toward the second end face. As for the solder layer and the junction layer, a portion of at least the solder layer is removed behind the second end face.

A semiconductor optical amplifier integrated laser includes a semiconductor laser oscillator portion that oscillates laser light having a wavelength included in a gain band and a semiconductor optical amplifier portion that amplifies laser light output from the semiconductor laser oscillator portion. The semiconductor laser oscillator portion and the semiconductor optical amplifier portion have one common p-i-n structure, the common p-i-n structure includes an active layer, a cladding layer provided apart from the active layer, and a common functional layer formed in the cladding layer, and the common functional layer includes a first portion that reflects light having a wavelength within the gain band in the semiconductor laser oscillator portion and a second portion that transmits light having a wavelength within the gain band in the semiconductor optical amplifier portion.

A laser diode chip has a laser facet, which includes a coating. The coating includes an inorganic layer and an organic layer. In one example, the coating has a number of inorganic layers, including a heat-conductive layer. For example, the inorganic layers may form a reflection-increasing or reflection-decreasing layer sequence.

A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

The semiconductor laser element includes: a substrate; a first semiconductor layer disposed above a main surface of the substrate; an active layer that is disposed above the first semiconductor layer and generates light; and a second semiconductor layer) disposed above the active layer. In a top view of a front-side end portion of the semiconductor laser element from which the light is emitted, an end surface of the second semiconductor layer includes an inclined portion with respect to an end surface of the first semiconductor layer.

A laser device for use with a display including a plurality of pixels is disclosed. The laser device includes a gain section and a modulator. The gain section is electrically coupled with a first current or voltage source. The gain section is configured to selectively amplify an optical power of light reflecting within the gain section based on a first drive current or voltage supplied from the first current or voltage source to the gain section. The modulator is optically coupled with the gain section. The modulator is electrically coupled with a second current or voltage source. The modulator is configured to selectively attenuate or amplify an optical power of light received from the gain section based on a second drive current or voltage supplied from the second current or voltage source to the modulator. Light emitted from the modulator is provided to the display.

A controller stabilizes a distributed feedback plus reflection (DFB+R) laser, which has a back facet, a DFB section, a passive section, and a front facet with a low reflective element. An etalon filter is formed by a portion of the DFB section, the passive section, and the low reflective element. Control circuitry directly modulates the DFB section with a modulation signal and biases the passive section with a bias signal. In operation, a lasing mode of the DFB section is aligned to a long wavelength edge of one of the periodic peaks of a reflection profile of the etalon filter. Meanwhile, photodiodes are arranged to monitor the output power emitted from the laser's front and back facets. The control circuitry monitors a ratio of the detected output power and adjusts the bias based on the monitored ratio.