PURPOSE: To allow a reflected light to be accurately made incident on a waveguide from a surface to be detected by using the waveguide constituted so as to become a single mode waveguide or a double mode waveguide according to a polarization direction of light.
CONSTITUTION: The annealing is performed to both side areas 6a, 6b and 3a, 4a of the single mode waveguide 5 after a proton is exchanged, and a second core part is formed. The areas 3a, 4a become the single mode waveguides 3, 4 for distribution, and the areas 5a, 6a, 67b covering first, second core parts become the double mode waveguide 7. Since only abnormal light beam is increased when the proton is exchanged, when the conditions of the proton exchange and the annealing are selected properly, the waveguide 5 and the areas 6a, 6b become the single mode waveguide 7 for a waveguide light of a normal light beam and become the double mode waveguide 7 for the waveguide light of the abnormal light beam. A completely combined length is defined as Lc, and the length L of a double mode area is decided to be a prescribed length, and the arrangement of a laser light beam source and a substrate is decided. When the outgoing light quantities from the waveguides 3, 4 are differential-amplified, the condensing deviation of light is detected.
| JP7281471 | optical element |
| JP5410001 | Silicon-based Schottky Barrier Infrared Photodetector |
| WO/2004/106998 | POLYMER OPTICAL WAVEGUIDE AND OPTICAL DEVICE |
IWASAKI JUN
SHIONOYA TAKASHI
OKI YASUSHI
