Electrically polarised domain prodn. in substrate - by laser beam heating ferroelectric substrate in electric field

摘要

Prodn. of domains, which are electrically polarised in various directions, in a substrate, esp. for optical (frequency multiplication, involves local laser beam (2) heating of a ferroelectric substrate (1) to above its Cura temp. (Tc) in an electric field (E) aligned in one or other direction (r1,r2) to produce the individual polarised domains. Pref. the substrate (1) consists of BaTiO4, PbTiO4 or pref. LiNbO3. USE/ADVANTAGE - The domains are useful for quasi-phase matching second harmonic generation (QPM-SHG) in semiconductor laser applications. The resulting waveguide structure has improved structure quality esp. the requisite mfd. fineness and precision, and employs a substrate formed homogeneously of ferromagnetic optically non-linear material.