40-Gb/s/ch operation of 1.3-μm four-wavelength lens-integrated surface-emitting DFB laser array

40-Gb/s/ch direct modulation of multi-wavelength 1.3-μm surface-emitting laser array is demonstrated. Fabricated laser array consisting of four-channel DFB stripes with modified gratings, 45° mirror, and integrated lens, exhibited clear 40-Gb/s eye openings over all four channels.