Abstract-Recent development of high-power widely tunable THz quantum cascade laser sources based on difference-frequency generation

M. Razeghi; Q. Y. Lu; N. Bandyopadhyay; S. Slivken

http://spie.org/Publications/Proceedings/Paper/10.1117/12.2192221


We present the recent development of high performance compact THz sources based on intracavity nonlinear frequency mixing in mid-infrared quantum cascade lasers. Significant performance improvements of our THz sources with respect to the continuous wave THz power output, monolithic THz tuning, and widely frequency are achieved by systematic optimization of the device's active region, waveguide design, and chip bonding strategy. Room temperature continuous wave THz power of more than 10 μW at 3.4 THz is demonstrated at room temperature. Monolithic THz tuning of a chip-based THz source from 2.6 to 4.2 THz with power up to 0.1 mW is achieved. Surface emission from the substrate via a diffraction grating with THz power up to 0.5 mW is also obtained. The developing characteristics show the potential for these THz sources as local oscillators for many astronomical and medical applications.

Abstract-Continuous operation of a monolithic semiconductor terahertz source at room temperature

Q. Y. Lu¹, N. Bandyopadhyay¹, S. Slivken¹, Y. Bai¹ and M. Razeghi^1,a)
http://scitation.aip.org/content/aip/journal/apl/104/22/10.1063/1.4881182
1 Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208, USA
a) Electronic mail: razeghi@eecs.northwestern.edu
Appl. Phys. Lett. 104, 221105 (2014); http://dx.doi.org/10.1063/1.4881182

We demonstrate room temperature continuous wave THz sources based on intracavity difference-frequency generation from mid-infrared quantum cascade lasers. Buried ridge, buried composite distributed-feedback waveguide with Čerenkov phase-matching scheme is used to reduce the waveguide loss and enhance the heat dissipation for continuous wave operation. Continuous emission at 3.6 THz with a side-mode suppression ratio of 20 dB and output power up to 3 μW are achieved, respectively. THz peak power is further scaled up to 1.4 mW in pulsed mode by increasing the mid-infrared power through increasing the active regiondoping and device area.

© 2014 AIP Publishing LLC

Abstract-Continuous operation of a monolithic semiconductor terahertz source at room temperature

Q. Y. Lu¹, N. Bandyopadhyay¹, S. Slivken¹, Y. Bai¹ and M. Razeghi^1,a)

¹ Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208, USA

^a) Electronic mail: razeghi@eecs.northwestern.edu

Appl. Phys. Lett. 104, 221105 (2014); http://dx.doi.org/10.1063/1.4881182

We demonstrate room temperature continuous wave THz sources based on intracavity difference-frequency generation from mid-infrared quantum cascade lasers. Buried ridge, buried composite distributed-feedback waveguide with Čerenkov phase-matching scheme is used to reduce the waveguide loss and enhance the heat dissipation for continuous wave operation. Continuous emission at 3.6 THz with a side-mode suppression ratio of 20 dB and output power up to 3 μW are achieved, respectively. THz peak power is further scaled up to 1.4 mW in pulsed mode by increasing the mid-infrared power through increasing the active regiondoping and device area.