Electrically driven frequency blue-chirped emission in Fabry–Perot cavity quantum cascade laser at room temperature

We present a method to produce fast frequency swept laser emission from monolithic mid-infrared laser. A commercially available Fabry–Pérot cavity quantum cascade (QCL) operating at wavelength of 8.15 ?m was electrically driven by current pulse with 10 ?s duration and slow front rising time ?2 ?s. Due the switching lasing vertical diagonal transition in QCL strong quantum-confined Stark effect energy shift transition, emitted light blue-shifting as injection continues raise above threshold. The temporal evolution spectrum measured high-resolution step-scan Fourier transform infrared spectrometer. blue-chirped strongly influenced heatsink temperature due high thermal sensitivity threshold slope efficiency. By optimizing carefully amplitude pulse, we demonstrate high-speed self-sweeping under room operation conditions, reaching spectral tuning range ?25 cm?1 within 1.8