Over 300 mW O-band 8-channel DFB laser array for optical I/O technology

A high-power distributed feedback laser array suitable for optical I/O applications is demonstrated. The epitaxial structure incorporates a high-refractive-index layer in the N-doped region to improve single-transverse-mode characteristics and reduce internal loss, enabling single-mode operation at a ridge width of 5 µm with an internal loss of 3 cm^-1. An asymmetric π-phase-shift, implemented using the reconstruction-equivalent chirp technique, ensures high single-mode yield. The fabricated array achieves output powers above 300 mW per channel at 25 °C with 800 mA injection current and exhibits uniform channel spacing with side mode suppression ratios exceeding 50 dB. Stable single-longitudinal-mode operation is maintained without mode hopping over a broad current and temperature tuning range. Under simultaneous operation at an injection current of 300 mA per channel, all channels of the laser array deliver output powers exceeding 100 mW, with an average wavelength deviation of 0.0692 nm. The devices further show a minimum Lorentzian linewidth of 300 kHz, and relative intensity noise of -154 dB/Hz, demonstrating strong potential for high-speed optical interconnects.