Fabrication of Surface Acoustic wave resonator as Acousto-optic Modulator

Acousto-optic modulation techniques are gaining edge in diverse applications in the area of agriculture, entertainment and defense. Present work focuses on indigenously developed pump probe technique to study the acousto-optic modulation using surface acoustic wave (SAW) device. For this study, SAW device has been fabricated on ST-cut quartz that is an optically nonlinear piezoelectric material. Coupling of acoustic wave with optical wave has been monitored and a visible modulation in the intensity of probe laser beam has been obtained. A clear shift in the value of probe intensity (similar to 12 mu W) is observed when surface acoustic waves are excited. Angular rotation of the fabricated SAW device under pump probe microscopy shows the periodicity of the nonlinearity in substrate while acoustic wave is propagating in it. The effect of variation in the intensity of pump laser beam on the acousto-optic modulation is also studied. The acousto-optic modulation behavior observed in surface acoustic devices in the present study demonstrates the possible application in telecommunication for signal modulation and in spectroscopy for frequency control.

Automated summary

This study focuses on the indigenous pump-probe technique to investigate acousto-optic modulation using a surface acoustic wave (SAW) device. A visible modulation in the intensity of the probe laser beam was observed through the monitoring of the coupling between acoustic wave and optical wave. The angular rotation of the SAW device showed the periodicity of the substrate's nonlinearity while the acoustic wave propagated in it. The study also examined the influence of variation in pump laser beam intensity on acousto-optic modulation. The observed acousto-optic modulation behavior in surface acoustic devices demonstrates potential applications in signal modulation for telecommunications and frequency control in spectroscopy.