System for studying power of laser beam

摘要

A laser beam power studying system for studying laser power in a reproducing mode and a recording mode of an optical recording apparatus. A laser beam having different powers in the recording mode and the reproduction mode is emitted and a first part of the laser beam is measured. A second part of the laser beam is measured by a front photo diode and a signal corresponding to the measurement by the front photo diode is amplified by a single amplifier in both reproducing recording study operations. Relational expression between measurements of the first part of the laser beam and the second part of the laser beam at different power levels of the laser beam is developed for both the recording and reproducing modes.