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Title: High-Temperature and High-Power Terahertz Quantum-Cascade Lasers.

Abstract

Abstract not provided.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1267116
Report Number(s):
SAND2007-0802C
524178
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the Conference Proceedings for the Photonics West Conference held January 22-26, 2007 in San Jose, CA.
Country of Publication:
United States
Language:
English

Citation Formats

Reno, John Louis, Williams, Benjamin S., Qin, Qi, Kumar, Sushil, and Hu, Qing. High-Temperature and High-Power Terahertz Quantum-Cascade Lasers.. United States: N. p., 2007. Web.
Reno, John Louis, Williams, Benjamin S., Qin, Qi, Kumar, Sushil, & Hu, Qing. High-Temperature and High-Power Terahertz Quantum-Cascade Lasers.. United States.
Reno, John Louis, Williams, Benjamin S., Qin, Qi, Kumar, Sushil, and Hu, Qing. Thu . "High-Temperature and High-Power Terahertz Quantum-Cascade Lasers.". United States. doi:. https://www.osti.gov/servlets/purl/1267116.
@article{osti_1267116,
title = {High-Temperature and High-Power Terahertz Quantum-Cascade Lasers.},
author = {Reno, John Louis and Williams, Benjamin S. and Qin, Qi and Kumar, Sushil and Hu, Qing},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 01 00:00:00 EST 2007},
month = {Thu Feb 01 00:00:00 EST 2007}
}

Conference:
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  • Terahertz quantum cascade lasers (QCLs) with a broadband gain medium could play an important role for sensing and spectroscopy since then distributed-feedback schemes could be utilized to produce laser arrays on a single semiconductor chip with wide spectral coverage. QCLs can be designed to emit at two different frequencies when biased with opposing electrical polarities. Here, we develop terahertz QCLs with bidirectional operation to achieve broadband lasing from the same semiconductor chip. A three-well design scheme with shallow-well GaAs/Al 0.10Ga 0.90As superlattices is developed to achieve high-temperature operation for bidirectional QCLs. It is shown that shallow-well heterostructures lead to optimalmore » quantum-transport in the superlattice for bidirectional operation compared to the prevalent GaAs/Al 0.15Ga 0.85As material system. Furthermore, broadband lasing in the frequency range of 3.1–3.7 THz is demonstrated for one QCL design, which achieves maximum operating temperatures of 147 K and 128 K respectively in opposing polarities. Dual-color lasing with large frequency separation is demonstrated for a second QCL, that emits at ~3.7 THz and operates up to 121 K in one polarity, and at ~2.7 THz up to 105 K in the opposing polarity. Finally, these are the highest operating temperatures achieved for broadband terahertz QCLs at the respective emission frequencies, and could lead to commercial development of broadband terahertz laser arrays.« less
  • Terahertz quantum cascade lasers with a record output power up to ∼0.23 W in continuous wave mode were obtained. We show that the optimal 2.9-mm-long device operating at 3.11 THz has a low threshold current density of 270 A/cm{sup 2} at ∼15 K. The maximum operating temperature arrived at ∼65 K in continuous wave mode and the internal quantum efficiencies decreased from 0.53 to 0.19 for the devices with different cavity lengths. By using one convex lens with the effective focal length of 13 mm, the beam profile was collimated to be a quasi Gaussian distribution.
  • No abstract prepared.
  • Quantum cascade lasers that operate in the underdeveloped terahertz spectral range (1-10 THz) promise to contribute to applications in sensing, spectroscopy, and imaging. We describe our development of terahertz quantum cascade lasers based on the resonant-phonon depopulation concept and that use low-loss metal-metal waveguides for optical confinement. Two- and three-dimensional finite-element simulations of terahertz metal-metal waveguides are used to demonstrate their high modal confinement even for very narrow ridges. Also, simulations predict high facet reflectivities due to the modal impedance mismatch with free space at the sub-wavelength waveguide aperture of these metal-metal waveguides. Finally, we report the demonstration of amore » 2.8 THz laser that operates up to 97 K in continuous-wave mode fabricated using a Cu-Cu thermocompression bonding technique.« less
  • Abstract not provided.