Spin-vertical-cavity surface-emitting lasers with by-design-defined birefringence for high-speed modulation.

Area of Science:

• Optoelectronics
• Semiconductor devices
• Photonics

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are crucial optoelectronic devices.
• Controlling polarization in VCSELs is essential for advanced applications.
• Birefringence engineering offers a pathway to tailor VCSEL polarization properties.

Purpose of the Study:

• To propose and investigate a new type of spin-VCSEL with designed birefringence.
• To explore the use of columnar thin films (CTFs) for birefringence control in VCSELs.
• To analyze the performance characteristics of these novel spin CTF-VCSELs.

Main Methods:

• Utilizing columnar thin films (CTFs) within the VCSEL structure (distributed Bragg mirror and/or cavity).
• Designing CTF-VCSELs with pre-defined birefringence.
• Calculating polarization-resolved resonant longitudinal modes, quantum-well confinement factors, and threshold gains.
• Employing the spin-flip VCSEL model for performance analysis.

Main Results:

• Successful design of spin-VCSELs with engineered birefringence using CTFs.
• Calculation of polarization-resolved modes and associated optical properties.
• Demonstration of potential for high-speed modulation response (3 dB cutoff frequency in the hundreds of GHz range) via spin-flip VCSEL model.

Conclusions:

• Columnar thin films (CTFs) provide an effective method for controlling birefringence in spin-VCSELs.
• The proposed spin CTF-VCSELs exhibit promising characteristics for high-frequency modulation.
• This work presents a new avenue for developing advanced polarization-controlled VCSELs.