| 摘要 |
A semiconductor laser drive system and a semiconductor laser driving method where both internal noise and optical feedback noise can be simultaneously reduced are provided at low cost and low power consumption. The semiconductor laser drive system in an optical pickup configured such that a turn light 9e from an irradiated object of a laser beam 9 emitted from a semiconductor laser 2 enters into the semiconductor laser 2 is composed of a drive circuit 3 for driving the semiconductor laser 2; an optical detector 6 for detecting light intensity of a laser beam 9b where the laser beam 9 emitted from the semiconductor laser 2 is ramified to convert the light intensity into an electric signal; and a feedback circuit that is composed of an amplifier circuit 7 and a filter circuit arranged between the drive circuit 3 and the light detector 6, and that applies electric negative feedback to the drive circuit 3 for reducing optical feedback noise if the frequency of the electric signal is within a frequency banc to be utilized as a signal, and that applies electric positive feedback to the drive circuit 3 for reducing internal noise if the frequency of the electric signal is outside the frequency band to be utilized as a signal.
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