A plasmonic SAW transducer

In this work, an acoustic-optical transducer that is based on the utilization of plasmons is proposed to optically detect SAW of wavelength (<400 nm) smaller than the optical wavelength (800 nm). Although grating based coupling of plasmons is well known, it has not been applied in the detection of ultrasound. In this work, designs utilizing this operating principle are proposed which can achieve higher changes in reflectivity than those achievable by traditional methods, thus overcoming the traditional difficulties in the detection of very high frequency (10 GHz range) SAWs. The proposed device can be fabricated on surfaces at low cost and be used to detect remotely.