Patent ID: 9088122
Filing Date: 2015-07-21
Classification: H01S

Abstract:
1. A driver circuit for an EA-DFB light-emitting device including a semiconductor laser diode (LD) with a type of a distributed feedback laser (DFB) integrated with an electro-absorption modulator (EA), said driver circuit comprising: a common cathode common to the LD and the EA, the common cathode electrically floating from the ground, a bias current source connectible between a relatively high voltage and the common cathode, the bias current source providing a bias current to the LD, a switching unit connectible between the common cathode and a relatively low voltage, the switching unit including a first current path and a second current path, the first current path including a resistor connected in parallel to the EA and a first transistor, the second current path including a second transistor and a diode connected in series to the second transistor, the first transistor and the second transistor being driven complementally and switching a modulation current, a first current source connected in parallel to the first transistor, the first current source draining a first bypass current through the resistor, a second current source connected in parallel to the second current path, the second current source draining a second bypass current from the common cathode, wherein the second current source is configured so that the bias current is equal to a sum of the first bypass current, the modulation current, and the second bypass current.