Design and Simulation of InGaN-Based Red Vertical-Cavity Surface-Emitting Lasers

Area of Science:

• Optoelectronics
• Materials Science
• Semiconductor Physics

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are crucial for optical communication and sensing.
• Achieving high polarization and efficiency in red-emitting VCSELs remains a challenge.
• Novel designs incorporating advanced materials and structures are needed to overcome current limitations.

Purpose of the Study:

• To propose and simulate a highly polarized red VCSEL (612 nm).
• To investigate the impact of nanoporous (NP) GaN distributed Bragg reflectors (DBRs) and TiO2 high-index contrast gratings (HCGs) on device performance.
• To provide design guidelines for efficient and bright red VCSELs.

Main Methods:

• Optoelectronic simulations were performed for a 612 nm VCSEL.
• The influence of NP DBR and HCG geometries on optical reflectivity was systematically analyzed.
• Cavity mode wavelength and optical threshold gain were investigated for finite-sized HCGs.

Main Results:

• Over 17 pairs of NP GaN DBRs with 60% air voids achieved >99.7% reflectance.
• Optimal HCG dimensions (period, width-to-period, height-to-period ratios) were identified.
• A large threshold gain difference (67.4-74%) between transverse modes was obtained, indicating high polarization.

Conclusions:

• The proposed VCSEL design with staggered InGaN multiple quantum wells, NP DBRs, and HCGs demonstrates potential for high polarization.
• Simulation results offer a roadmap for developing efficient and bright red VCSELs.
• The design considerations are critical for future optoelectronic device fabrication.