Nonvolatile polarization control of a bistable VCSEL

Area of Science:

• Optoelectronics
• Semiconductor devices
• Photonics

Background:

• Vertical-Cavity Surface-Emitting Lasers (VCSELs) are key components in optical communication.
• Controlling VCSEL polarization states is crucial for advanced optical functionalities.
• All-optical memory offers potential for high-speed data processing and storage.

Purpose of the Study:

• To experimentally demonstrate nonvolatile all-optical memory operation in a GaAs oxide-confined VCSEL.
• To investigate the control mechanisms for the dual polarization states.
• To assess the stability and limitations of the all-optical memory.

Main Methods:

• Utilizing two coexisting linear polarization states emitted from a GaAs oxide-confined VCSEL.
• Employing all-optical control methods including polarization selective feedback and crossed polarization reinjection.
• Injecting external light pulses to manipulate polarization states.
• Testing memory retention across varying pumping currents and substrate temperatures.

Main Results:

• Experimental evidence of nonvolatile all-optical memory operation was achieved.
• The dual polarization states were found to coexist over a wide range of operating conditions.
• All-optical control of polarization states was successfully demonstrated.
• Memory retention was confirmed after powering the VCSEL off and on, but lost upon substrate temperature variation.

Conclusions:

• GaAs oxide-confined VCSELs can function as nonvolatile all-optical memory devices.
• The demonstrated all-optical control methods are effective for manipulating memory states.
• Substrate temperature stability is critical for maintaining memory integrity.