An alternative sampling approach for continuous-wave (CW) terahertz homodyne systems applies wavelength-dependent phase-delay mirrors (WDPDM) to induce a frequency-dependent phase shift between transmitter and receiver arms of up to π/2. The THz field is sampled by shifting only the center frequency of the laser sources to maintain a constant frequency difference. With this technique, phase modulators are not required. Further, phase shift is unaffected by path length differences, and it is possible to measure dispersive samples without calibrating the arm length difference. Prior simulations in the C-band for a 280 GHz frequency difference were confirmed by experimental measurements.