| 摘要 |
PURPOSE: To remove the unbalance of the quantity of the incident light on plural photodetectors and to improve the quality and assembly characteristic of an optical head by adjusting the axes of polarization of a laser beam from a semiconductor laser and the transmission axis of polarization of an analyzer, then packaging the optical head. CONSTITUTION: Fig. illustrates an example that the actually measured axis 400 of polarization is rotates by 4 deg. with respect to the ideal axis 401 of polarization of the semiconductor exit light. This 4 deg. error is corrected by rotating the optical member 70 by 4 deg. and the semiconductor laser unit is packaged, by which the angle formed by the axis 400 of polarization and the transmission axes 410a, 410b of the polarization of a polarizing plate 80 is so corrected as to attain nearly 45 deg.. As a result, the light quantity ratio of the backward path luminous fluxes transmitting the polarizing plates 80a, 80b is suppressed down to <=5%. |
