Real time terahertz imaging through self mixing in a quantum cascade laser
We report on a fast self mixing approach for real time, coherent terahertz imaging based on a quantum cascade laser and a scanning mirror. Due to a fast deflection of the terahertz beam, images with frame rates up to several Hz are obtained, eventually limited by the mechanical inertia of the employed scanning mirror. A phase modulation technique allows for the separation of the amplitude and phase information without the necessity of parameter fitting routines. We further demonstrate the potential for transmission imaging.