A discretely tunable mode-locked laser with 32 wavelengths and 100-GHz channel spacing using an arrayed waveguide grating

We demonstrate a tunable mode-locked laser (time-to-wavelength mapped laser) with a 100-GHz channel spacing (1535.5-1560.5 nm) that uses a 32-wavelength silica-on-silicon planar lightwave circuit arrayed waveguide grating (AWG) for realizing a wavelength-dependent delay. The wavelength is selected by changing the mode-locking frequency. Mode-locking was realized by modulating the electroabsorption modulator (/spl sim/10 GHz) or the gain of the semiconductor amplifier (/spl sim/5 GHz). By matching the period of the Fabry-Perot resonances in the InGaAsP device with the channel spacing of the AWG, wavelength tuning was realized over a broad wavelength range by only changing the mode-locking frequency.