Patent ID: 6195370
Filing Date: 2001-02-27
Classification: H01S

Abstract:
An optical transmission device, comprising:a laser diode;a current supply circuit for supplying a bias current and a modulating current superimposed on the bias current to said laser diode as driving currents;an automatic optical output control circuit for supplementing the shortage of the driving currents so that emission power of said laser diode is held constant;a temperature detection circuit for detecting an ambient temperature of said laser diode;memory means for storing driving control data for determining a modulating current and a bias current necessary to obtain predetermined emission power therein for each predetermined temperature; andcontrol means for obtaining driving control data corresponding to the temperature detected by said temperature detection circuit from said memory means, controlling each driving current, to be supplied from said current supply circuit to said laser diode, based on the obtained driving control data, measuring each driving current actually supplied to said laser diode whose emission power is held constant by said automatic optical output control circuit, detecting whether the difference between the measured driving current and a driving current determined according to the driving control data corresponding to the detected temperature at that time exceeds an allowable range, and updating the driving control data related to the temperature, on said memory means when said difference exceeds the allowable range so that the difference between the driving currents is defined as each of increases in bias current and modulating current.