Patent ID: 7483455
Filing Date: 2009-01-27
Classification: H01S

Abstract:
1. A control method for a laser diode, wherein optical output and OMA (optical modulation amplitude) or extinction ratio of the laser diode are controlled while modulating the optical output of the laser diode by applying a bias current and a modulation current to the laser diode, comprising: a first step of measuring the optical output of the laser diode, the optical output being integrated to generate an average value from optical outputs of the laser diode; a second step of measuring a slope efficiency or a corresponding value of the slope efficiency by a ratio of a variation of the optical output and a variation of the bias current in optical output measurement value while conducting APC (automatic power control) to adjust the bias current such that the optical output coincides with a predetermined value; and a third step of adjusting the modulation current by AAC (automatic amplitude control) according to the modulation current calculated with the slope efficiency or the corresponding value of the slope efficiency such that the OMA or extinction ratio coincides with a predetermined value, wherein monitoring of the optical output measured in the first step is continued after the third step to be fed back, and wherein the second step and the third step are repeated when the optical output does not coincide with the predetermined value, until the optical output coincides with the predetermined value.