Measurement of microwave frequency based on polarization interference by measuring DC voltage

Abstract

Abstract We experimentally demonstrate a photonic microwave frequency measurement based on polarization interference by measuring DC voltage. Time delay is introduced into two electric signals which serves as driving signals of the parallel Mach–Zehnder modulators. After polarization interference, the amplitude of DC output is related to the microwave frequency. Thus, the system can identify the input frequency avoiding high-speed and wideband detectors. In the measurement with one polarization interference, the measurement range and resolution can be optimized using wavelength division multiplexing. The measurement range of 0-26\xa0GHz with measurement errors within 0.2\xa0GHz and 26-40\xa0GHz with errors within 0.4\xa0GHz are achieved. In the measurement with orthogonal polarization interference, the measurement range and resolution is tunable by adjusting the time delay. The measurement range of 2.1-9.6\xa0GHz with measurement errors within 0.3\xa0GHz and 5.4-23.4\xa0GHz with errors within 0.35\xa0GHz are achieved.