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.