Frequency modulation

Frequency modulation

      In the photoelectric signal detection, it is often interfered by many signals, and even the intensity of the interfered signal is much higher than that of the measured signal.At this point, if you know the frequency of the useful signal, you can use the phase-locked amplifier to measure the signal submerged in the noise.The chopper modulator can provide reference signal for phase-locked amplifier.

      By modulating the optical signal, the chopper modulates the transaction variable signal of the optical radiation signal and outputs the square wave of reference voltage synchronizing with the modulation frequency, thus providing an accurate reference signal for the PLL amplifier so that the PLL amplifier can identify the useful weak signal.