Patent ID: 7502568

Claim:
A system comprising: a light source capable of emitting light at a variable output power to transmit data at a given data rate; a monitor diode positioned to receive at least a portion of the emitted light, the monitor diode having a bandwidth only partially overlapping a lower end of a data transmission spectrum for the data rate; and a controller capable of determining an average output power of the light source based on an output signal of the monitor diode, comparing the average output power to a target value, and adjusting the variable output power of the light source by: incrementing or decrementing a logical 1 level current based on the comparison of the average output power to the target value; and determining a modulation current for the light source using the incremented or decremented logical 1 level current; wherein the average output power and at least one of an optical modulation amplitude and an extinction ratio of the light source are controlled based on values of the transmitted data contained in the emitted light.