Patent ID: 7224709

Claim:
An electrical circuit for a directly modulated semiconductor radiation source, comprising: a semiconductor radiation source having a modulated current supplied thereto based on a digital data signal, wherein the falling signal edge of the current exhibits peaking; circuit means connected to an electrical contact point of the circuit and operable to reduce or prevent peaking of the falling signal edge of the current when a forward voltage across the semiconductor radiation source falls below a predetermined level, wherein the circuit means comprises a discharge pulse controller that reduces peaking of the falling signal edge of the current by means of corresponding control of peaking pulses, wherein the discharge pulse controller supplies a voltage or current signal to a circuit providing peaking when the forward voltage falls below the predetermined level, said voltage or current signal switching off peaking of the edge considered, and wherein the discharge pulse controller comprises a comparator that compares a voltage across the electrical contact point with a predetermined voltage value and generates a voltage or current signal which is supplied to the circuit providing peaking when the voltage across the electrical contact point is greater than the predetermined voltage value.