Patent ID: 6895028
Filing Date: 2005-05-17
Classification: H01S

Abstract:
1. A light-emitting element controller which controls a semiconductor light-emitting element driven by a driving current including a bias current component and a pulse current component, comprising: a current-optical output coefficient deriving unit which derives a current-optical output coefficient η representing a correspondence relation between the amount of change in current supplied to said semiconductor light-emitting element and the amount of change in optical output, based on average optical output information representing a time average of the optical output of said semiconductor light-emitting element driven by a driving current Id including a bias current component Ib and a pulse current component Ip; a pulse current determining unit which determines the pulse current component Ip of said driving current, based on the derived current-optical output coefficient η, a predetermined target average optical output value PavO, and a predetermined target extinction ratio ER0; and a bias current determining unit which determines the bias current component Ib of said driving current, based on the average optical output information of said semiconductor light-emitting element driven by said driving current Id including the determined pulse current component Ib so that the average optical output represented by said average optical output information matches said predetermined target average optical output, within a predetermined range.