A5059546475- Spectroscopy and Laser Applications
- Semiconductor Lasers and Optical Devices
- Semiconductor Quantum Structures and Devices
- Photonic and Optical Devices
- Laser Design and Applications
- Advanced Semiconductor Detectors and Materials
- Advanced Fiber Laser Technologies
- Solid State Laser Technologies
- GaN-based semiconductor devices and materials
- Photonic Crystals and Applications
- Chalcogenide Semiconductor Thin Films
- Atmospheric Ozone and Climate
- Thermal Radiation and Cooling Technologies
- Plasmonic and Surface Plasmon Research
- Quantum and electron transport phenomena
- solar cell performance optimization
- ZnO doping and properties
- Optical Coatings and Gratings
- Photorefractive and Nonlinear Optics
- Analytical Chemistry and Sensors
- Strong Light-Matter Interactions
- Advanced Sensor Technologies Research
- Atmospheric and Environmental Gas Dynamics
- Magnetic and transport properties of perovskites and related materials
- Nanowire Synthesis and Applications
United States Naval Research Laboratory
2016-2025
Optical Sciences (United States)
2012-2025
K Lab (United States)
1998-2023
California Institute of Technology
2021
Wrocław University of Science and Technology
2021
AGH University of Krakow
2021
United States Navy
2009-2019
University of California, Santa Barbara
2017
Naval Research Laboratory Optical Sciences Division
2012
Optica
1998-2008
We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, InN, along with their ternary quaternary alloys. Based on review existing literature, complete consistent parameter sets are given all materials. Emphasizing quantities required structure calculations, we tabulate direct indirect energy gaps, spin-orbit, crystal-field...
We present a comprehensive and up-to-date compilation of band parameters for all the nitrogen-containing III–V semiconductors that have been investigated to date. The two main classes are: (1) “conventional” nitrides (wurtzite zinc-blende GaN, InN, AlN, along with their alloys) (2) “dilute” (zinc-blende ternaries quaternaries in which relatively small fraction N is added host material, e.g., GaAsN GaInAsN). As our more general review semiconductor [I. Vurgaftman et al., J. Appl. Phys. 89,...
Abstract The excitation of surface-phonon-polariton (SPhP) modes in polar dielectric crystals and the associated new developments field SPhPs are reviewed. emphasis this work is on providing an understanding general phenomenon, including origin Reststrahlen band, role that optical phonons lattices play supporting sub-diffraction-limited how relatively long phonon lifetimes can lead to low losses observed within these materials. Based overview, achievements attained date potential...
Plasmonics provides great promise for nanophotonic applications. However, the high optical losses inherent in metal-based plasmonic systems have limited progress. Thus, it is critical to identify alternative low-loss materials. One polar dielectrics that support surface phonon polariton (SPhP) modes, where confinement of infrared light aided by phonons. Using fabricated 6H-silicon carbide nanopillar antenna arrays, we report on observation subdiffraction, localized SPhP resonances. They...
We review the current status of interband cascade lasers (ICLs) emitting in midwave infrared (IR). The ICL may be considered hybrid a conventional diode laser that generates photons via electron–hole recombination, and an intersubband-based quantum (QCL) stacks multiple stages for enhanced efficiency. Following brief historical overview, we discuss theoretical aspects active region core designs, growth by molecular beam epitaxy, processing broad-area, narrow-ridge, distributed feedback (DFB)...
Excitation of localized surface plasmons in metal nanostructures generates hot electrons that can be transferred to an adjacent semiconductor, greatly enhancing the potential light-harvesting capabilities photovoltaic and photocatalytic devices. Typically, external quantum efficiency these hot-electron devices is too low for practical applications (<1%), physics underlying this yield remains unclear. Here, we use transient absorption spectroscopy quantify initial electron transfer model...
The mid-infrared spectral region, 2–20 μm, is of great interest for sensing and detection applications, in part because the vibrational transition energies numerous molecules fall that region. Silicon photonics a promising technology to address many these applications on single integrated, low-cost platform. Near-infrared light sources, heterogeneously integrated silicon, have existed more than decade, there been incorporations optical devices silicon platforms. However, no lasers fully onto...
The midwave infrared interband cascade laser (ICL) can operate at threshold power densities 30 times lower than those of the quantum laser. This is ultimately attributable to much longer carrier lifetime, rather specifics cavity dimensions and mirror reflectivities. ICL therefore an attractive candidate for insertion into portable, battery-powered chemical sensors now being developed this spectral region. We review characteristics ICLs operating wavelengths from 2.9 5.5 μm, show that their...
We review the history, development, design principles, experimental operating characteristics, and specialized architectures of interband cascade lasers for mid-wave infrared spectral region. discuss present understanding mechanisms limiting ICL performance provide a perspective on potential future improvements. Such device properties as threshold current power densities, continuous-wave output power, wall-plug efficiency are compared with those quantum laser. Newer classes such frequency...
We show that the polariton density of states in planar optical cavities strongly coupled to vibrational excitations remains much lower than even at frequency and upper polaritons under most practical circumstances. The is higher within a narrow window only when inhomogeneous line width least an order magnitude smaller Rabi splitting. Therefore, modification reaction rates via density-of-states pathway appears small or negligible for scenarios reported literature. While bounded from above by...
Since their inception, optical frequency combs have transformed a broad range of technical and scientific disciplines, spanning time keeping to navigation. Recently, dual comb spectroscopy has emerged as an attractive alternative traditional Fourier transform spectroscopy, since it offers higher measurement sensitivity in fraction the time. Midwave infrared (mid-IR) are especially promising effective means for probing strong fundamental absorption lines numerous chemical biological agents....
The authors propose two novel sources emitting in the mid-IR: type-II and type-I interband cascade lasers, perform detailed gain calculations. High radiative efficiencies are expected, since phonon processes which dominate relaxation intersub-band quantum laser effectively eliminated.
A new W-structured type-II superlattice photodiode design, with graded band gap in the depletion region, is shown to strongly suppress dark currents due tunneling and generation-recombination processes. The long-wave infrared (LWIR) devices display 19%–29% quantum efficiency substantially reduced currents. median dynamic impedance-area product of 216Ωcm2 for 33 10.5μm cutoff at 78K comparable that state-of-the-art HgCdTe-based photodiodes. sidewall resistivity ≈70kΩcm untreated mesas also...
Two different approaches, a photoconductive response technique and correlation of lasing thresholds with theoretical threshold carrier concentrations have been used to determine Auger lifetimes in InAs/GaInSb quantum wells. For energy gaps corresponding 3.1–4.8 μm, the room-temperature coefficients for seven samples are found be nearly an order-of-magnitude lower than typical type-I results same wavelength. The data imply that at this temperature, rate is relatively insensitive details band...
We report a five-stage interband cascade laser that operates at λ=3.75μm in cw mode up to maximum temperature of 319K. With gold electroplating, epitaxial-side-up mounting, and one facet coated for high reflectivity, 3mm×9.2μm ridge emits over 10mW power 300K.
Results are presented for an enhanced type-II W-structured superlattice (WSL) photodiode with 11.3μm cutoff and 34% external quantum efficiency (at 8.6μm) operating at 80K. The new WSL design employs quaternary Al0.4Ga0.49In0.11Sb barrier layers to improve collection by increasing minority-carrier mobility. By fitting the efficiencies of a series p-i-n photodiodes background-doped i-region thicknesses varying from 1to4μm, authors determine that electron diffusion length is 3.5μm. structures...
Room temperature spasing of surface plasmon polaritons at 1.46 μm wavelength has been demonstrated by sandwiching a gold-film plasmonic waveguide between optically pumped InGaAs quantum-well gain media. The spaser exhibits narrowing, the expected transverse-magnetic polarization, and mirror feedback provided cleaved facets in 1-mm long cavity fabricated with flip-chip approach. 1.06-μm pump-threshold ~60 kW/cm2 is good agreement calculations. architecture readily adaptable to all-electrical...
We discuss the state-of-the-art performance of interband cascade lasers emitting in 3–5 μm spectral band. Broad-area devices with five active stages display pulsed threshold current densities as low 400 A cm−2 at room temperature. Auger decay rates are extracted from analysis and differential slope efficiencies nearly 30 lasers, found to be significantly lower than was anticipated based on prior information. New designs also produce ICLs room-temperature internal losses ≈6 cm−1. The...
The interband cascade laser (ICL) concept provides robust and efficient emission in the midwave infrared spectral band. While geometry is somewhat analogous to that of a quantum employing intersubband transitions, ICL implementation exploits type-II band alignment GaSb-based material system. A semimetallic overlap at boundary between electron hole injector regions automatically generates carriers with densities tunable by confinement. Electrical injection then replenishes already present...