Phase-locking a THz quantum cascade laser to a THz comb through an all-optical beating
Authors: Consolino L., Bartalini S., Cancio P., Taschin A., Bartolini P., Vitiello M., Tredicucci A., Torre R., De Natale P.
Autors Affiliation: LENS, European Laboratory for NonLinear Spectroscopy, Via N. Carrara 1, Sesto Fiorentino (FI), I-50019, Italy; INO, Istituto Nazionale di Ottica, CNR, Largo E. Fermi 6, Firenze, I-50125, Italy; NEST, Istituto Nanoscienze, Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, I-56127, Italy
Abstract: We demonstrate the phase-locking of a 2.5 THz Quantum Cascade Laser (QCL) to an air-propagating, 6 octaves-spanning, THz Optical Frequency Comb Synthesizer (OFCS). We directly observe the beating signal using a commercial detector, therefore proving that this approach provides a mature metrological tool in the THz region. We show that only a small fraction (<100 nW) of the radiation emitted from the QCL is sufficient to generate a beat-note suitable for the phase-lock to the comb. These results pave the way to metrological-grade THz applications, especially in view of QCLs operating at higher temperatures. © 2012 IEEE.
Conference title: 37th International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2012
More Information: Sponsors: Office of Naval Research Science and Technology; UOW Engineering, School of Engineering Physics; Centre for Ultrahigh bandwidth Devices for Optical Systems; Edinburgh Photonics; TYDEXKeyWords: Metrological tools; Optical frequency combs; Phase-lock; Phase-locking; THz quantum cascade lasers, Frequency bands; Lasers; Quantum cascade lasers; Terahertz waves, Laser mode locking