| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser diode module capable of reducing a tracking error without using a tracking error compensating circuit and suitable for making a device small and reliable. SOLUTION: In an LD module 15, a laser diode 11 as a light emitting element and a single-mode quartz fiber 12 as a transmission medium are used. The laser diode 11 is driven by a LD driving circuit 16, and the LD driving circuit 16 is controlled by an automatic optical output control circuit 17 to stabilize optical output power. Through the automatic optical output control circuit 17, the LD driving circuit 16 is controlled on the basis of optical output power detected by an optical output power detecting photo-diode 13. A crystal liquid 14 put between the optical output power detecting photo-diode 13 and the laser diode 11. In the temperature characteristics, the crystal liquid 14 has transmittance for compensating a tracking error. |
