Light-emitting element controller, optical transmitting apparatus, and method and computer program for determining driving current
AssigneeKabushiki Kaisha Toshiba
InventorMitsuru Sugawara
Life of this patent
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Abstract
A pulse current component of a driving current is determined, based on a current-optical output coefficient derived using average optical output information of a semiconductor light-emitting element. A bias current component can be set by adjusting an average optical output of the semiconductor light-emitting element while changing the bias current component by the driving current including the determined pulse current component. Since the current-optical output coefficient can be derived based on the average optical output under wide conditions, both the pulse current component and the bias current component can be determined under the wide conditions and without using a quick-response light detector.
Claims14
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 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;
- a pulse current determining unit which determines the pulse current component of said driving current, based on the current-optical output coefficient derived by said current-optical output coefficient deriving unit;
- and
- a bias current determining unit which determines the bias current component of said driving current, based on the average optical output information of said semiconductor light-emitting element driven by said driving current including the pulse current component determined by said pulse current determining unit.
A driving current determining method for determining a driving current of a semiconductor light-emitting element driven by the driving current including a bias current component and a pulse current component, comprising:
- deriving a current-optical output coefficient representing a correspondence relation between the current for driving said semiconductor light-emitting element and an optical output;
- determining the pulse current component, based on the derived current-optical output coefficient;
- controlling the driving current, based on the determined pulse current;
- and
- determining the bias current component, based on the optical output of said semiconductor light-emitting element driven by the controlled driving current.
An computer program executed in a computer for performing the driving current determining method for determining a driving current of a semiconductor light-emitting element driven by the driving current including a bias current component and a pulse current component, comprising:
- deriving a current-optical output coefficient representing a correspondence relation between the current for driving said semiconductor light-emitting element and an optical output;
- determining the pulse current component, based on the derived current-optical output coefficient;
- controlling the driving current, based on the determined pulse current;
- and
- determining the bias current component, based on the optical output of said semiconductor light-emitting element driven by the controlled driving current.
Dependencies are inferred from the claim text.