Fig. 4: mmWave generation from broadband QCL (QCL2).
From: Millimeter wave photonics with terahertz semiconductor lasers
a Full amplitude spectrum showing THz emission centred at 2.8 THz with a bandwidth of 800 GHz and nonlinear mmWave generation up to 500 GHz. Inset - fundamental electrical beatnote from THz QCL detected using the QCL as a detector and a spectrum analyser. b Enhanced view of mmWave intensity spectrum (red) compared to simulated emission for THz spectrum with measured phases (blue) and assuming equal phases (black). Spectra offset for clarity. The QCL is driven in pulsed mode (10% duty cycle) and at a fixed heat sink temperature of 10 K.
