PURPOSE: To obtain an optical demultiplexer easy of the adjustment of an optical axis and the polishing of end surfaces by forming a geodesic lens and a diffraction grating on the same quartz substrate and providing said substrate with an enbedded type waveguide constitution.
CONSTITUTION: A geodesic lens 4 having a recessed part consisting of depth (h) and a radius R is formed on a quartz substrate 1 and the surface of the lens 4 is laminated with a clad layer 3. The light having various kinds of wavelength which is led from input optical fibers 6 is made incident to the geodesic lens 4 while being expanded and is diffracted by a diffraction grating 5 under diffracting conditions corresponding to respective wavelength. Respective diffracted light is stopped against by the geodesic lens 4 and is made incident to output optical fibers 7.
NODA JIYUICHI
OKAMOTO KATSUNARI
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