Narrow-linewidth 1.55-µm-wavelength InP-based photonic-crystal surface-emitting lasers with near-diffraction-limited...

Area of Science:

• Semiconductor Lasers
• Photonics
• Optoelectronics

Background:

• Photonic-crystal surface-emitting lasers (PCSELs) are promising for various applications.
• Achieving simultaneous narrow linewidth, high power, and excellent beam quality in PCSELs remains a challenge.

Purpose of the Study:

• To demonstrate 1.55-µm-wavelength InP-based PCSELs with superior performance.
• To investigate the potential of large-area single-mode lasing in 2D photonic crystals for enhanced laser characteristics.

Main Methods:

• Fabrication of InP-based PCSELs utilizing two-dimensional photonic crystals.
• Characterization of laser performance, including spectral linewidth, output power, and beam quality (M² factor).
• Analysis of linewidth dependence on output power under continuous-wave operation.

Main Results:

• Demonstrated PCSELs with narrow spectral linewidth (35 kHz at >300 mW output).
• Achieved high output power (>300 mW) with near-diffraction-limited beam quality (M² < 1.1).
• Observed stable single-mode operation enabling a symmetric, circular beam with low divergence (approx. 0.6°).

Conclusions:

• The developed PCSELs exhibit excellent performance, combining narrow linewidth, high power, and superior beam quality.
• These PCSELs are suitable for coherent free-space optical (FSO) communication, LiDAR, and optical fiber systems.
• The results validate the effectiveness of large-area single-mode lasing in 2D photonic crystals for advanced laser design.