Patent ID: 8521019

Claim:
A system for providing closed loop control of an optical link, comprising: a transmitter for generating an optical signal; an optical fiber for transmitting the optical signal, having a first end for receiving the optical signal from the transmitter and a second end for outputting the optical signal; a receiver for receiving the optical signal from the second end of the optical fiber; a sensor for measuring the mean power of the optical signal received by the receiver for a predetermined desired level of the optical signal generated by the transmitter; feedback means for providing a signal from the receiver to the transmitter in the form of a current which is proportional to the mean power of the optical signal received at the input of the receiver after transmission by the optical fiber; a comparator for comparing the mean power of the signal received by the receiver to the predetermined desired level of the optical signal transmitted by the transmitter; and a controller for determining the threshold voltage of the laser diode and the modulation levels to be applied to the laser diode such that the extinction ratio and signal swing of the launched power signal result in a received signal to noise ratio within the receiver which achieves a predetermined bit error rate.