Three-coherent-output narrow-linewidth and tunable single frequency 1x2 multi-mode-interferometer laser diode.

Area of Science:

• Photonics and Laser Technology
• Semiconductor Device Engineering

Background:

• Coherent light sources are essential for various optical applications.
• Existing multi-output laser technologies often face challenges in cost, complexity, and performance.

Purpose of the Study:

• To design and fabricate a 1x2 multi-mode-interferometer (MMI) laser diode.
• To achieve tunable, single-frequency coherent outputs with high performance metrics.
• To explore cost-effective manufacturing methods for advanced MMI laser configurations.

Main Methods:

• Design and fabrication of a 1x2 multi-mode-interferometer (MMI) laser diode.
• Characterization of output coherence, frequency tunability, side mode suppression ratio (SMSR), and linewidth.
• Evaluation of manufacturing processes, specifically avoiding material regrowth and high-resolution gratings.

Main Results:

• Demonstrated three coherent outputs with tunable single-frequency emission.
• Achieved >30dB side mode suppression ratio (SMSR) and a 25nm tuning range (C and L bands).
• Measured a narrow linewidth of 750 kHz.

Conclusions:

• The fabricated 1x2 MMI laser diode successfully provides multiple coherent outputs with superior performance.
• The design offers a scalable platform for 1xN or MxN MMI lasers for advanced coherent sources.
• The fabrication process, avoiding material regrowth and gratings, significantly enhances yield and reduces cost.