A system and method for tuning and infrared source laser in the Mid-IR wavelength range. The system and method comprising, at least, a plurality of individually tunable emitters, each emitter emitting a beam having a unique wavelength, a grating, a mirror positioned after the grating to receive at least one refracted order of light of at least one beam and to redirect the beam back towards the grating, and a micro-electro-mechanical systems device containing a plurality of adjustable micro-mirrors.

A quantum cascade laser device includes a semiconductor substrate, an active layer provided on the semiconductor substrate, and an upper clad layer provided on a side of the active layer opposite to the semiconductor substrate side and having a doping concentration of impurities of less than 1×10.sup.17 cm.sup.−3. Unit laminates included in the active layer each include a first emission upper level, a second emission upper level, and at least one emission lower level in their subband level structure. The active layer is configured to generate light having a center wavelength of 10 μm or more due to electron transition between at least two levels of the first emission upper level, the second emission upper level, and the at least one emission lower level in the light emission layer in each of the unit laminates.

A laser assembly (1710) for generating an assembly output beam (1712) includes a laser subassembly (1716) including a first laser module (1716A) and a second laser module (1716B), a transform assembly (1744), and a beam combiner (1746). The first laser module (1716A) emits a plurality of spaced apart first laser beams (1720A). The second laser module (1716B) emits a plurality of spaced apart second laser beams (1720B). The transform assembly (1744) is positioned in a path of the laser beams (1720A) (1720B). The transform assembly (1744) directs the laser beams (1720A) (1720B) to spatially overlap at a focal plane of the transform assembly (1744). The beam combiner (1746) is positioned at the focal plane that combines the lasers beams (1720A) (1720B) to provide a combination beam. The laser beams (1720A) (1720B) directed by the transform assembly (1744) impinge on the beam combiner (1746) at different angles.

According to various embodiments, a system for stabilizing operation of semiconductor laser frequency combs via optical feedback is disclosed. The system includes an external cavity having a beam-splitter, polarizer, and mirror or partially reflective element mounted on a translational stage. The external cavity and a laser facet of the semiconductor laser form an external optical resonator for coupling light to a laser cavity.

A quantum cascade laser element includes: a semiconductor substrate; a semiconductor laminate including an active layer having a quantum cascade structure; a first electrode formed on a surface on an opposite side of the semiconductor laminate from the semiconductor substrate; a second electrode; and an insulating film formed on at least one end surface of a first end surface and a second end surface of the semiconductor laminate. The first electrode includes a first metal layer made of a first metal, and a second metal layer made of a second metal having a higher ionization tendency than that of the first metal. The first metal layer has a first region exposed to an outside. The second metal layer has a second region located on one end surface side with respect to the first region. The insulating film reaches the second region from the one end surface.

An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/−10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.

A QCL may include a substrate, an emitting facet, and semiconductor layers adjacent the substrate and defining an active region. The active region may have a longitudinal axis canted at an oblique angle to the emitting facet of the substrate. The QCL may include an optical grating being adjacent the active region and configured to emit one of a CW laser output or a pulsed laser output through the emitting facet of substrate.

A portable lighting apparatus is provided with a gallium-and-nitrogen containing laser diode based white light source combined with an infrared illumination source which are driven by drivers disposed in a printed circuit board assembly enclosed in a compact housing and powered by a portable power supply therein. The portable lighting apparatus includes a first wavelength converter configured to output a white-color emission and an infrared emission. A beam shaper may be configured to direct the white-color emission and the infrared emission to a front aperture of a compact housing of the portable lighting apparatus. An optical transmitting unit is configured to project or transmit a directional light beam of the white light emission and/or the infrared emission for illuminating a target of interest, transmitting a pulsed sensing signal or modulated data signal generated by the drivers therein. In some configurations, detectors are included for depth sensing and visible/infrared light communications.

Systems and methods for sensing vibrational absorption induced photothermal effect via a visible light source. A Mid-infrared photothermal probe (MI-PTP, or MIP) approach achieves 10 mM detection sensitivity and sub-micron lateral spatial resolution. Such performance exceeds the diffraction limit of infrared microscopy and allows label-free three-dimensional chemical imaging of live cells and organisms. Distributions of endogenous lipid and exogenous drug inside single cells can be visualized. MIP imaging technology may enable applications from monitoring metabolic activities to high-resolution mapping of drug molecules in living systems, which are beyond the reach of current infrared microscopy.

A quantum cascade laser includes a laser structure having an output face for emitting laser light in a first direction; and a lens having an entrance surface and a convex surface, the entrance surface receiving the laser light from the output face, and the convex surface emitting the laser light after being condensed by the lens. The laser structure includes a semiconductor substrate and a mesa waveguide provided on a first region of a principal surface of the semiconductor substrate, the mesa waveguide extending in the first direction. The lens includes a semiconductor and is provided on a second region of the principal surface of the semiconductor substrate. The first region and the second region are arranged in the first direction.