PURPOSE: To actively match phases of a fundamental optical wave and a harmonic optical wave to each other by forming gaps between light-transmissive materials of plural waveguides and adjusting gap dimensions to adjust the effective refractive index.
CONSTITUTION: A waveguide 12 or 12' includes a nonlinear material through which the light energy of a fundamental frequency or a harmonic frequency can be transmitted. The are arranged so as to face each other so that a coupling gap 18 having prescribed nominal dimensions (d) is formed between surfaces of light-transmissive materials. When a variable force is applied to one of substrates 12 and 12', gap dimensions (d) are changed to change the refractive index for a specific noticed wavelength. At this time, spacers 16 and 16' are made of compressible materials, and the substrate 12" is made sufficiently thick so that it cannot bend, and surfaces facing each other of higher harmonic generation layers 14 and 14' are kept approximately parallel. Thus, phases of the fundamental optical wave and the internally generated harmonic optical wave are actively matched to each other in a wide range of dimensional and physical changes.
RICHIYAADO EI SUTORUTSUENBAAGA
JIYON JIYOSEFU ZORA
