Asymmetric waveguide and compressively strained quantum well-enabled high-power, polarization-dependent 850 nm gain...

Area of Science:

• Optoelectronics
• Semiconductor Lasers
• Materials Science

Background:

• Hybrid-integrated narrow-linewidth lasers are essential for quantum sensing and atomic cooling.
• Current lasers face power limitations hindering advanced applications.
• High-power gain chips are critical for overcoming these limitations.

Purpose of the Study:

• To design and demonstrate a high-power Gallium Arsenide (GaAs)-based gain chip for the 850 nm wavelength band.
• To address power limitations in hybrid-integrated narrow-linewidth lasers.
• To provide a viable solution for high-power laser development in the 850 nm spectrum.

Main Methods:

• Utilized an asymmetric waveguide design.
• Incorporated compressively strained quantum wells.
• Employed advanced epitaxial growth and low-loss waveguide techniques.

Main Results:

• Achieved a record continuous-wave output power of 114.08 mW.
• Obtained a broadband spectrum of 31.55 nm with low spectral modulation.
• Demonstrated enhanced power and reduced cavity loss via asymmetric waveguide, suppressing carrier leakage.
• Improved polarization extinction ratio using compressive strain-induced valence band splitting.

Conclusions:

• The developed GaAs-based gain chip offers a significant advancement for high-power hybrid-integrated lasers in the 850 nm band.
• The asymmetric waveguide design effectively enhances power and minimizes cavity loss.
• Compressive strain engineering optimizes polarization characteristics, making this a practical solution for demanding applications.