Electronic driver circuit for directly modulated semiconductor lasers

Abstract

An electronic driver circuit for directly modulated semiconductor lasers is described. The drive circuit has a first circuit for generating a constant current and a second circuit for modulating the constant current. The second circuit generates, as a function of a digital data signal, a modulation current that is superimposed on the constant current, the modulated current being fed to a semiconductor laser. According to the invention, a third circuit is additionally provided which keeps the driver circuit at a low impedance during a rising edge and/or a falling edge of the current through the semiconductor laser. As a result, the signal shape of the optical output signals of the semiconductor laser can be improved, and the driver circuit can be operated at higher data rates, in particular at data rates of up to 12 Gbit/s.

Dependencies are inferred from the claim text.