Patent ID: 8180216

Claim:
A device, comprising: a tunable laser to generate an optical signal at a particular wavelength; an optical modulator to modulate the optical signal based on a modulation signal; an output port to output the modulated optical signal to a test optical path; an input port to receive a return optical signal following propagation through the test optical path; latency calculating logic to calculate an optical latency for the test optical path based on the modulation signal and the return optical signal; and a controller to receive user selections for the tunable laser and the modulation signal and configured to initiate calculation of the optical latency by the latency calculating logic, wherein the user selections for the modulation signal further comprise at least one of a pulse width associated with the modulation signal or a pulse period associated with the modulation signal, wherein the pulse width or the pulse period is selected such that a maximum measurable latency is less than the pulse period.