Fig. 14From: Integrated heterodyne laser Doppler vibrometer based on stress-optic frequency shift in silicon nitrideSetup for vibration measurements. A probe-head from Polytec was utilized for focusing and collecting the light from the vibrating surface. For real-time demodulation a synchronization signal was shared between the driver of the speaker and the demodulation circuit. PC: Polarization controller, PHs: Phase heaters, AWG: Arbitrary waveform generatorBack to article page