Frequency tuning characteristics and WDM channel access of the semiconductor three-branch Y3-lasers

We describe frequency tuning and channel access characteristics of the new, widely-tunable, multi-quantum-well three-branch Y3-lasers. The Y3-lasers are tuned discretely with two independent current controls: coarse tuning (5.5 nm, 680 GHz tuning steps) selects the desired optical frequency range, fine tuning selects the desired frequency channel (0.4 nm, 50 GHz channel spacing). For example, we demonstrate access to 50 channels over the /spl sim/31 nm free spectral range of the Y3-laser; 36 contiguous channels are accessed using three independent current controls. The coarse/fine "digital" tuning makes Y3-lasers very useful for wavelength-division-multiplexed (WDM) multi-channel optical communication systems.<
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