Simultaneous CW Operation of Shared Angular Dispersive Element WDM Lasers

We show that when more than two channels operate continuous-wave simultaneously in shared dispersive element wavelength-division-multiplexing lasers with uniform channel spacing, chi sup ((3)) in the passive shared waveguide can cause spontaneous fluctuations in frequency and power. We propose the simple cure of making the shared waveguide extremely short. We obtain a value for the magnitude of the nonlinear-index coefficient of our InGaAsP waveguides of 0.9 x 10 sup (-12) cm sup 2 /W.