Kyocera Corporation

Shinji Inoue

Hiroyuki Kinoshita

Satoru Tsubokura

Kazushi Kamiyama

Takashi Uto

Shin Murakami

Takayuki Shimizu

Akihiko Kataoka

Tetsuo Niwa

On a substrate made of a single crystal of La.sub.3 Ga.sub.5.5 Nb.sub.0.5 O.sub.14, an excitation electrode 2 for generating a surface acoustic wave is provided to produce a surface acoustic wave device S. The cutting angles of the substrate and the direction of propagation of the surface acoustic wave are defined in Eulerian angle indication (.phi., .theta., .psi.) by .phi.=50.degree.+60.degree..times.m1, .theta.=125.degree.+180.degree..times.m2 and .psi.=40.degree.+180.degree..times.m3 (where m1, m2 and m3 are integers). Eulerian angles may be .phi.=10.degree.+60.degree..times.n1, .theta.=125.degree.+180.degree..times.n2, and .psi.=70.degree.+180.degree..times.n3 (where n1, n2 and n3 are integers) or .phi.=a1+60.degree..times.b1, .theta.=a2+180.degree..times.b2 and .psi.=a3+180.degree..times.b3 (where 0.degree..ltoreq.a1.ltoreq.60.degree., 125.degree..ltoreq.a2.ltoreq.165.de gree., 110.degree..ltoreq.a3.ltoreq.165.degree., and b1, b2 and b3 are integers).

Surface acoustic wave device

A hemispheric lens of a single crystal having a refractive index of 2.0 or over is used as a SIL lens of an optical system for optical recording. The single crystal is LiNbO3, LiTaO3, rutile phase TiO2, PbMoO4, TeO2, SrTiO3, ZrO2, SrNbO3, SrTaO3, CaNbO3, CaTaO3, CaTiO3, KNbO3, KTaO3, BaZrO3, SrZrO3, CaZrO3, KNbO3, KTaO3, BaZrO3, SrZrO3, CaZrO3, ZnWO4, ZnMoO4, CdWO4, CdMoO4, PbWO4, Bi20SiO12, Bi20GeO12, Bi4Si3O12, Bi4Ge3O12, GaP, ZnTe, ZnSe, Cu3TaSe4 or ZnS.

Optical system for optical recording

Growing community of inventors

Souraku-gun, Japan

Shinji Inoue