Vertical-cavity surface-emitting laser with a liquid crystal external cavity.

Area of Science:

• Optoelectronics
• Materials Science
• Laser Physics

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are key components in optical communication and sensing.
• External cavities offer a method to tune VCSEL emission properties.
• Liquid crystals (LCs) provide voltage-tunable optical characteristics.

Purpose of the Study:

• To develop a VCSEL with an electrically tunable external cavity using nematic liquid crystals.
• To investigate the control of VCSEL emission properties (polarization and wavelength) via voltage.
• To achieve stable and high-contrast polarization switching.

Main Methods:

• Integration of a nematic liquid crystal layer and dielectric reflector as an external cavity on a VCSEL.
• Application of voltage across the liquid crystal layer to alter its optical path length.
• Characterization of the VCSEL's emission properties (wavelength, polarization) as a function of applied voltage.

Main Results:

• Demonstration of voltage-controlled tuning of the VCSEL's optical path length.
• Successful modulation of emission wavelength and polarization state by applied voltage.
• Achieved stable polarization switching with high contrast through voltage driving.

Conclusions:

• The developed liquid crystal-VCSEL (LC-VCSEL) device enables electrically tunable emission.
• This technology is suitable for applications requiring precise control over VCSEL output.
• The device offers a promising solution for integrated, voltage-controlled optoelectronic systems.