Simultaneous CW operation of shared angular dispersive element WDM lasers

We show that when more than two channels operate continuous-wave (CW) simultaneously in shared dispersive element wavelength-division-multiplexing (WDM) lasers, /spl 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 nonlinear-index coefficient of our InGaAsP waveguides of +0.9/spl times/10/sup -12/ cm/sup 2//W.