Driver circuits of the present invention provide current to drive laser diodes.
The output current of the driver circuit includes a data signal and a low frequency
tone signal. The low frequency tone signal is within the bandwidth of a power control
feedback loop. The tone signal introduces low frequency noise into the output signal
of the driver circuit. The low frequency noise causes jitter at the zero crossing
points of the driver circuit output signal. A laser driver circuit of the present
invention provides a compensation current to a laser diode. The compensation current
is out of phase with the tone signal. The compensation current eliminates the low
frequency noise in the output signal of the laser driver circuit.