High-power, narrow-linewidth, thermally tuned multi-channel interference tunable laser based on butt-joint regrowth...

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Telecommunications

Background:

• Next-generation coherent communication systems require lasers with high output power, narrow linewidth, and precise tunability.
• Existing laser technologies face challenges in meeting the demanding specifications for data rates of 800 Gbit/s and beyond.

Purpose of the Study:

• To demonstrate a monolithically integrated, thermally tuned multi-channel interference (MCI) laser optimized for high-performance coherent optical systems.
• To achieve high output power, narrow linewidth, wide tuning range, and enhanced reliability through innovative integration and thermal tuning techniques.

Main Methods:

• Monolithic integration using butt-joint regrowth for low-loss active-passive device coupling.
• Implementation of air-gap suspended phase sections for efficient thermal tuning.
• Precise common-phase tuning for frequency stability and characterization of tuning speed.

Main Results:

• Achieved a facet output power of 120 mW and a minimum Lorentzian linewidth of 40 kHz.
• Demonstrated a tuning range exceeding 56 nm, side-mode suppression ratio (SMSR) > 49 dB, and fiber-coupled output power up to 18.1 dBm.
• Exhibited excellent reliability with < ±30 pm drift over 5000 hours aging at 100°C and a tuning response time below 250 µs.

Conclusions:

• The butt-joint regrowth integrated MCI laser meets critical performance metrics for 800 Gbit/s and future coherent communication systems.
• The device's high power, narrow linewidth, wide tuning, and reliability make it a promising candidate for advanced optical networks.
• This work advances integrated laser technology for high-capacity optical data transmission.