Patent ID: 6055251
Filing Date: 2000-04-25
Classification: H01S

Abstract:
A driving method for frequency-modulating a semiconductor laser by directly injecting modulation current having a modulation frequency into the semiconductor laser, said semiconductor laser being provided with at least first and second electrodes through each of which current is injected, said driving method comprising the steps of:injecting a first modulation current through the first electrode when the modulation frequency is in a first frequency band; andwhen the modulation frequency is in a second frequency band lower than the first frequency band, injecting the first modulation current through the first electrode and injecting a second modulation current, which is anti-phase with the first modulation current injected through the first electrode, through the second electrode, and when the modulation frequency is in the first frequency band, the second modulation current which is anti-phase with the first modulation current is not injected through said second electrode.