High power lateral coupled InAs/GaAs quantum dot distributed feedback lasers grown on Si(001) substrates.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• High-quality single-frequency semiconductor lasers are crucial for silicon optical integrated systems.
• Quantum dot (QD) lasers offer unique properties for optoelectronic applications.
• Integration of lasers on silicon substrates is a key goal for photonic advancements.

Purpose of the Study:

• To demonstrate a high output power, low noise, and feedback-insensitive 1.3 µm InAs/GaAs QD distributed feedback (DFB) laser grown on silicon.
• To characterize the performance of the QD DFB laser across a range of temperatures.
• To showcase a multi-channel QD DFB laser array for integrated photonic applications.

Main Methods:

• Utilized high density 8-stacked quantum dot (QD) material.
• Incorporated low-loss laterally coupled gratings.
• Grew InAs/GaAs QD distributed feedback (DFB) lasers on Si(001) substrates.

Main Results:

• Achieved high single-mode output power up to 25 mW at 20 °C and 1.8 mW at 70 °C.
• Maintained stable single-mode operation with a maximum side mode suppression ratio (SMSR) of 56.5 dB.
• Demonstrated low relative intensity noise (-155.9 dB/Hz) and a narrow Lorentzian linewidth (243 kHz).
• Exhibited insensitivity to optical feedback (-24.9 dB).
• Presented a 7-channel QD DFB laser array with SMSRs > 45 dB.

Conclusions:

• The developed QD DFB laser on silicon meets critical performance metrics for integrated photonics.
• This technology enables practical, high-performance single-frequency silicon-based light sources.
• The results pave the way for advanced silicon photonic chips and systems.