Continuous wave (CW) terahertz technology has long interested astronomers because approximately one-half of the total luminosity and 98% of the photons emitted since the Big Bang fall into the submillimeter and far-infrared, and CW THz sources can be used to help study these photons. Submillimetre (terahertz) astronomy is the prime technique to unveil the birth and early evolution of a broad range of astrophysical objects. It is a relatively new branch of observational astrophysics which focuses on studies of the cold Universe, i.e., objects radiating a significant, if not dominant, fraction of their energy at wavelengths ranging from 100 micron to 1 mm. THz continuum observations are particularly powerful to measure the luminosities, temperatures and masses of cold dust emitting objects. Examples of such objects include star-forming clouds in our Galaxy, prestellar cores and deeply embedded protostars, protoplanetary disks around young stars, as well as nearby starburst galaxies and dust-enshrouded high-redshift galaxies in the early Universe. In THz Astronomy, high power CW local oscillators driving multi-pixel heterodyne receivers at key frequencies (e.g. 1.4, 1.9, 2.7 THz) could be deployed on space and sub-orbital platforms.
A room temperature CW narrow-line THz TECSEL source capable of delivering mW powers at any targeted frequency across the THz gap has the potential to address a broad swath of applications in THz Astronomy, spectroscopy, security and remote explosive detection, nondestructive testing and medicine.
Desert Beam is funded through a NSF SBIR Phase 1 grant IIP-0912824 entitled A Portable High-Power Tunable Terahertz Source using a Two-Color VECSEL and a NASA Phase 1 and Phase 2 SBIR High Power Room Temperature Terahertz Local Oscillator. The Phase 2 project started on June 1, 2011.
In the news
June 2011: Compact, high-power, room-temperature, narrow-line terahertz source THz waves have been notoriously difficult to generate and, consequently, this remains a relatively unexplored part of the electromagnetic spectrum. They also do not propagate far through the atmosphere, except in narrow transmission bands at selected frequencies. CW THz sources are highly desirable for a wide range of applications, from THz astronomy to spectroscopy, biosensing, and security and quality inspection in various industries, as well as for medical and pharmaceutical purposes. A SPIE Newsroom article is a available at:
"Compact, high-power, room-temperature, narrow-line terahertz source"
February 2011: Room-temperature source yields record-power terahertz beam A nonlinear optics device, developed in conjunction with Desert Beam Technologies, could help to resolve one of astronomy's lingering blind spots. A Search and Discovery Article on this development has appeared in the February issue of Physics Today.
"Room-temperature source delivers record-power terahertz beam", Physics Today, Volume 64, pp. 13-15, February, 2011.
January 10, 2011: Record power in the terahertz gap
Desert Beam Technologies LLC has designed a room-temperature terahertz external-cavity surface-emitting laser, or TECSEL, that delivers narrowband, milliwatt beams at terahertz-gap frequencies. The source achieved record power by positioning all the necessary photomixing elements—the nonlinear crystal; a Brewster window, which polarizes light; and an etalon, which establishes two IR lasing frequencies—inside the laser cavity.
"Record power in the terahertz gap", Physics Today, Physics Update, January 10, 2011.