Spin injection enhancement in CW VECSEL at room temperature using push-pull optical pumping.

Area of Science:

• Optoelectronics
• Spintronics
• Semiconductor Lasers

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are crucial optoelectronic devices.
• Efficient spin injection is key for advanced spintronic applications.
• Current methods for spin polarization in VCSELs have limitations.

Purpose of the Study:

• To enhance spin injection efficiency in external-cavity VCSELs.
• To investigate a novel double pumping scheme for improved spin control.
• To analyze the impact of polarized optical resonant illumination on spin polarization.

Main Methods:

• Utilizing a non-resonant pumping method.
• Coupling non-resonant pumping with polarized optical resonant illumination.
• Experimentally measuring laser polarization states and ellipticity.

Main Results:

• Achieved enhanced spin injection efficiency through a double pumping scheme.
• Demonstrated control over spin orientation for electron/hole recombination.
• Observed a significant increase in laser ellipticity (approx. 50%) compared to non-resonant pumping alone.
• Experimentally confirmed polarization state flips with specific ellipticities (+31° for spin down, -33° for spin up).

Conclusions:

• The proposed double pumping scheme effectively enhances spin injection efficiency in VCSELs.
• This technique offers precise control over spin polarization for laser processes.
• The findings pave the way for more efficient spintronic devices based on VCSELs.