Surface acoustic wave reflection from diamond-like carbon thin film reflecting arrays on LiNbO3 substrates

Surface acoustic wave (SAW) reflection from diamond-like carbon (DLC) strip reflecting arrays on Y-Z LiNbO3 is investigated. The reflection from DLC strips with triangular cross section has been observed. Reflection increases in alternating DLC and Al strips in 90 degrees reflecting arrays in comparison with pure Al structures. The values of reflection coefficient per period in the slanted reflecting arrays are estimated to be about 1.0% for pure DLC strips (height to wavelength ratio equal to 0.02), 2% for uniform Al coating on DLC reflecting arrays, and 3.5% for alternating DLC and Al strips. This value is higher than that for pure Al strips by about 0.7%. Reflection properties are briefly discussed, and preparation technique is presented.