Patent ID: 8385749

Claim:
A method comprising: biasing a laser diode at a bias current above a lasing threshold of said laser diode; applying a modulation signal to said laser diode to produce a first output optical signal having first and second signal power levels corresponding to first and second signal states, splitting said first output optical signal into first and second branch signals; providing a first phase shift to said first signal state of said first branch signal; providing a second phase shift to said second signal state of said first branch signal; and, combining said first branch and second branch signals to produce a second output optical signal, said combining causing a constructive interference between said first signal states of said first and second branch signals, and a destructive interference between said second signal states of said first and second branch signals, resulting in a new set of first and second signal power levels, wherein said second output optical signal exhibits an improved extinction ratio represented by said new set of first and second signal power levels over that of said first output optical signal.