Microwave Frequency Measurement Based on an Optically Injected Semiconductor Laser
Bowen Zhang, Dan Zhu, Hao Chen, Yuewen Zhou, Shilong Pan
Abstract
A microwave frequency measurement system utilizing the optical injection technology in a semiconductor laser is proposed. A single-wavelength optical carrier is generated and divided into two parts. One part is intensity-modulated by a control signal with a triangular shape and then injected into a semiconductor laser to generate a frequency scanning optical sideband. The other part is modulated by the microwave signal under test, which is then coupled with the frequency scanning optical sideband and detected by a photodetector (PD). The output of the PD is filtered by an electrical passband filter and detected by an envelope detector. Electrical pulses will be obtained with the time interval proportional to the microwave frequency. Thus the microwave frequency can be retrieved from the time interval of the generated pulses. A proof of concept experiment is taken. The microwave frequency measurement from 3 to 40 GHz is achieved, and the frequency measurement errors are within ±30 MHz.