Abstract-Broadband all-electronically tunable MEMS terahertz quantum cascade lasers

Ningren Han, Alexander de Geofroy, David P. Burghoff, Chun Wang I. Chan, Alan Wei Min Lee, John L. Reno, and Qing Hu  »View Author 

Optics Letters, Vol. 39, Issue 12, pp. 3480-3483 (2014)
http://dx.doi.org/10.1364/OL.39.003480

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-12-3480

In this work, we demonstrate all-electronically tunable terahertz quantum cascade lasers (THz QCLs) with MEMS tuner structures. A two-stage MEMS tuner device is fabricated by a commercial open-foundry process performed by the company MEMSCAP. This provides an inexpensive, rapid, and reliable approach for MEMS tuner fabrication for THz QCLs with a high-precision alignment scheme. In order to electronically actuate the MEMS tuner device, an open-loop cryogenic piezo nanopositioning stage is integrated with the device chip. Our experimental result shows that at least 240 GHz of single-mode continuous electronic tuning can be achieved in cryogenic environments (∼4  K) without mode hopping. This provides an important step toward realizing turn-key bench-top tunable THz coherent sources for spectroscopic and coherent tomography applications.

© 2014 Optical Society of America

WIPO PUBLISHES PATENT OF LONGWAVE PHOTONICS FOR "MULTI-SPECTRAL TERAHERTZ SOURCE AND IMAGING SYSTEM" (AMERICAN INVENTOR)

GENEVA, Oct. 5 -- Publication No. WO/2013/148368 was published on Oct. 3.

http://www.laserfocusworld.com/news/2013/10/08/wipo-publishes-patent-of-longwave-photonics-for-multi-spectral-terahertz-source-and-imaging-system-a.html

Title of the invention: "MULTI-SPECTRAL TERAHERTZ SOURCE AND IMAGING SYSTEM." Applicants: LONGWAVE PHOTONICS LLC (US). Inventors: Alan Wei Min Lee (US). According to the abstract* posted by the World Intellectual Property Organization: "A broadly tunable semiconductor laser source having at least two semiconductor lasers, composed of dissimilar gain media, positioned in close proximity to one another, with an optical element for collimating the output of the semiconductor lasers, and a dispersive element to overlap the collimated beams with a microelectronic controller, which switches each laser on and off and sets the bias conditions for each laser. The output beams can be made parallel by design of the grating dispersion in combination with the lens, with small aiming corrections provided by mechanical actuation of the grating. The tunable source can be used for spectroscopy and spectroscopic imaging over a broad frequency range where the gain media are chosen for emission at frequencies of interest." The patent was filed on March 15 under Application No. PCT/US2013/032611. *For further information, including images, charts and tables, please visit:

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