QUASI-PHASE-MATCHED OPTICAL WAVEGUIDES AND METHOD OF MAKING SAME

摘要

PCT No. PCT/SE89/00595 Sec. 371 Date Jun. 24, 1991 Sec. 102(e) Date Jun. 24, 1991 PCT Filed Oct. 25, 1989 PCT Pub. No. WO90/04807 PCT Pub. Date May 3, 1990.A waveguide in optically nonlinear materials for quasi-phase-matched frequency conversion of electromagnetic waves, arranged in a crystal substrate. The waveguide includes a periodically alternating crystal orientation necessary for quasi-phase-matching. The crystal orientation is provided in the form of a periodically domain inverted structure of ferroelectric domains, with reversed crystal orientation in relation to intermediate regions located between the domains. The domain structure is achieved by use of a periodic mask structure applied to the surface of the substrate in combination with a subsequent heat treatment of the substrate.