Chirped Mirrors

In THz homodyne systems, optical delay is often realized through mechanical delay lines, which are expensive and complex, thus limiting industrial applications. The use of wavelength-dependent phase-delay (DMS) mirrors allows for a controllable phase shift at 280 GHz solely by tuning the frequencies of both lasers. This replaces the mechanical delay line, potentially increases measurement speed, and enables the measurement of frequency-dependent samples, as the difference frequency of the lasers remains unchanged during tuning.