Low-Threshold InP Nanowire Hetero-Photonic Crystal Surface-Emitting Lasers.

Area of Science:

• Semiconductor Nanostructures
• Photonic Integrated Circuits
• Optoelectronics

Background:

• Nanowire photonic crystal surface-emitting lasers (PCSELs) are promising on-chip coherent light sources.
• Existing PCSELs face challenges in laser performance and active region compactness.

Purpose of the Study:

• To design and evaluate InP nanowire hetero-PCSELs for improved laser characteristics.
• To address the demand for compact and high-performance on-chip light sources.

Main Methods:

• Designed InP nanowire hetero-PCSELs with a compact hexagonal inner lasing region (1.5–15 μm side lengths).
• Incorporated a larger, off-resonant outer photonic crystal to reduce the lasing threshold.
• Investigated lasing characteristics of PCSELs with varying inner region sizes relative to pump light focus.

Main Results:

• Inner PCSELs with side lengths >3 μm and area smaller than pump focus showed reduced threshold power and gain.
• Threshold reduction attributed to enhanced back reflection at the heterolattice interface.
• Laser energy was confined within the forbidden photonic gap of the outer photonic crystal.

Conclusions:

• Hetero-PCSEL design significantly enhances laser performance and compactness.
• This approach enables ultracompact, low-threshold nanowire PCSELs.
• The findings facilitate integration into advanced photonic circuits.