| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hologram recording and playback device controlling a light beam from an external resonator type semiconductor laser to enhance diffraction efficiency. <P>SOLUTION: The hologram recording and playback device includes: a laser diode 7 for recording having an external resonator type laser for generating data light and reference light to be irradiated on a hologram disk 1, a photo diode detecting a detection light quantity showing a quantity of a light beam from the external resonator type laser, a laser driving circuit supplying current to the external resonator type laser, and a laser diode control part controlling the laser driving circuit so that an integrated light quantity obtained by integrating the detection light quantity for a predetermined time is made equal to a predetermiend recording energy. <P>COPYRIGHT: (C)2010,JPO&INPIT |
