Compact monolithic high-power narrow-linewidth multi-wavelength DFB laser array for optical I/O applications

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Lasers
• Integrated Optics

Background:

• Dense Wavelength Division Multiplexing (DWDM) systems require compact, high-power, and power-balanced light sources.
• Existing laser arrays often face challenges with output power, uniformity, and integration.

Purpose of the Study:

• To propose and demonstrate a novel compact monolithic four-wavelength distributed feedback (DFB) laser array.
• To achieve high output power, excellent power uniformity, and precise wavelength control for DWDM applications.

Main Methods:

• Utilized a parallel laser connection with a two-stage Y-branch combiner for wavelength merging.
• Integrated a semiconductor optical amplifier (SOA) for power boosting.
• Employed the reconstruction equivalent chirp (REC) technique for wavelength control and a slab-coupled optical waveguide (SCOW) structure for low loss and single-mode operation.

Main Results:

• Achieved output powers exceeding 100 mW per wavelength with < 0.039 nm wavelength deviation.
• Demonstrated side-mode suppression ratios > 35 dB and linewidths < 530 kHz.
• Obtained relative intensity noise (RIN) below -145 dB/Hz and clear 25 Gb/s NRZ eye diagrams.

Conclusions:

• The demonstrated laser array is a promising high-power, narrow-linewidth, and power-balanced light source.
• The device is suitable for demanding DWDM optical input/output (I/O) applications.
• The integrated design and advanced techniques ensure high performance and reliability.