Terahertz spectrum analyzer based on frequency and power measurement

We demonstrate a terahertz (THz) spectrum analyzer based on frequency and power measurement. A power spectrum of a continuous THz wave is measured through optical heterodyne detection using an electromagnetic THz frequency comb and a bolometer and power measurement using a bolometer with a calibrated responsivity. The THz spectrum analyzer has a frequency precision of 1×10−11, a frequency resolution of 1Hz, a frequency band up to 1.7THz, and an optical noise equivalent power of ~1 pW/Hz1/2.