Pulse Optimization and Control of Quantum Cascade Laser via an All-Optical Approach

Pulse optimization and control are demonstrated in a standard middle-infrared quantum cascade laser by illuminating its front facet with two near-infrared lasers. The 1550- and 850-nm near-infrared lasers are used to optimize the pulse rise/fall time and the pulse shape, respectively, of the quantum cascade laser. Compared with the electric drive, the electron interband transition is directed by the all-optical approach. Simultaneously, the quantum cascade laser's pulse width, amplitude, and repetition rate are controlled precisely by changing the two near-infrared lasers' delay time, average power, and repetition rate. Such an all-optical approach is beneficial in the high-speed optimization and control of the quantum cascade laser pulse. It has the potential for application in free-space optical communication and high-speed frequency modulation spectroscopy.