Pranalytica, Inc.

Other

Harvard College

Alexei Tsekoun

C Kumar N Patel

Richard Maulini

Arkadiy Lyakh

Federico Capasso

Michael B Pushkarsky

Laurent Diehl

Christian Pflugl

Ilya Dunayevskiy

Manu Prasanna

Rowel C Go

Qijie Wang

An improved longwave infrared quantum cascade laser. The improvement includes a strained InGaAs/AlInAs composition, with x and y each between 0.53 and 1, an active region emitting at a wavelength equal to or greater than 8 &#x3bc;m, an energy spacing Eequal to or greater than 50 meV, an energy spacing Eequal to or greater than 250 meV, and an optical waveguide with a cladding layer on each side of the active region. Each cladding layer has a doping level of about 2&#xb7;10cm. The optical waveguide also has a top InP layer with a doping level of about 5&#xb7;10cmand a bottom InP layer with a doping level of about 5&#x2003;10cm. Additionally, the optical waveguide has a plasmon layer with a doping level of about 8&#xb7;10cm.

Long wavelength quantum cascade lasers based on high strain composition

An improved quantum cascade laser, the improvement comprising a longitudinally non-uniform dielectric waveguide. The waveguide includes a longitudinally straight section and a longitudinally tapered section. The length of the tapered section is between 5% and 50% of the total cavity length. The tapered section tapers at a taper angle from the facet width to the ridge width. The taper angle is smaller than the delineation angle of the waveguide.

Tapered waveguide high-power quantum cascade lasers

A quantum cascade laser (QCL) having a bias-neutral design and a semiconductor with multiple layers of AlInAs/InGaAs. The first active region barrier has a thickness of less than fourteen angstroms, and the second active region barrier has a thickness of less than eleven angstroms. The lower active region wavefunction overlaps with each of the injector level wavefunctions. Also, the laser transition is vertical at a bias close to roll-over. The injector level' is above a lower laser level, the injector level&#x2032; is below the lower laser level, and the active region levelis confined to the active region. The lower laser levelis separated from the active region levelby the energy of the LO phonon. The remaining active region states and the remaining injector states are either above the lower laser levelor significantly below the active region level

Quantum cascade laser: bias-neutral design

A submount for a semiconductor laser. The submount has a layer of silicon carbide (SiC) and a layer of aluminum nitride (AlN) deposited on the layer of SiC. The submount is bonded to the InP-based laser by a hard solder applied to the AlN layer. Preferably, the thickness of the AlN layer is ten to twenty microns, the thickness of the SiC layer is two hundred fifty microns, and the solder is a gold-tin (AuSn) eutectic. The semiconductor laser may be a quantum cascade laser (QCL). Similar combinations of submount materials can be found for other semiconductor laser material systems and types.

Submounts for Semiconductor Lasers

A quantum cascade laser utilizing non-resonant extraction design having a multilayered semiconductor with a single type of carrier; at least two final levels (and) for a transition down from level; an energy spacing Egreater than E; an energy spacing Eof about 100 meV; and an energy spacing Eabout equal to E. The carrier wave function for leveloverlaps with the carrier wave function for level. Likewise, the carrier wave function for level' overlaps with the carrier wave function for level. In a second version, the basic design also has an energy spacing Eof about 90 meV, and levelsand&#x2032; do not have to be spatially close to each other, provided that levelhas significant overlap with both these levels. In a third version, there are at least three final levels (, and) for a transition down from level. Each of the levels, andhas a non-uniform squared wave function distribution.

Quantum cascade laser

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.

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Los Angeles, CA, United States of America

Alexei Tsekoun