Microwave electro-optical imaging system using a frequency tracking optical local oscillator source with a polarization CMOS image sensor

In this study, we developed a high-frequency electric field imaging system based on the first-order electro-optic effect for the detection of time-varying frequency wave sources. The proposed system utilizes the optical heterodyne technique. The process begins with an antenna that detects the frequency of the electric field of interest, which is then fed into the optical local oscillator (LO) signal generation system. This optical LO signal tracks the frequency of the electric field being observed while maintaining a constant intermediate frequency. This configuration enables the visualization of dynamic electric fields, including asynchronous wave sources and frequency-modulated signals, without requiring a direct physical connection to the wave source.