| 摘要 |
PURPOSE:To improve the detection efficiency of a magneto-optical signal to wavelength fluctuation, to enhance signal detection sensibility and to reduce noises by mounting a photodetector formed on the underside side of an optical guide layer detecting light separated into a TE mode and a TM mode by a waveguide beam splitter. CONSTITUTION:The outgoing light of a semiconductor laser 22 is collimated by a collimating lens 23, and entered to a prism coupler 21, and light not coupled with an optical guide layer 17 is reflected and emitted from the prism coupler 21, and applied to a magneto-optical disk 25 by an objective 24 and recording, etc., are conducted. Reflected light from the magneto-optical disk 25 is made incident to the objective 24 again the collimated, then made incident to the prism coupler 21 and wave-guided in the optical guide layer 17, and made incident to a waveguide beam splitter 18. A TM mode light is received by a photodetector 20 and a TE mode light by a photodetector 19, and magneto- optical signals are obtained. Accordingly, the detection efficiency of a magneto- optical signal to wavelength fluctuation and signal detection sensibility are improved, and noises are reduced. |
