Room temperature continuous wave THz quantum cascade laser source with high power operation

We demonstrate the first room temperature continuous wave THz sources based on intracavity difference frequency generation from mid-infrared quantum cascade lasers. This accomplishment was enabled by integration of several key technologies, resulting in a new high efficiency waveguide design and improved thermal dissipation. Room temperature single mode emissions at 3.6 THz with an emitting power of 3 mu W and a mid-IR-to-THz conversion efficiency of 0.44 mW/W-2 are obtained in continuous wave mode. THz peak power up to 1.4 mW in pulsed mode operation with a mid-IR-to-THz conversion efficiency of 0.8 mW/W-2 at 3.5 THz is also demonstrated.