Dynamics of dual-polarization VCSEL-based optical frequency combs under optical injection locking

Area of Science:

• Optoelectronics
• Photonics
• Laser Physics

Background:

• Vertical-cavity surface-emitting laser (VCSEL) diodes are crucial for compact optical systems.
• Optical frequency combs (OFCs) are essential for precise optical measurements and communications.
• Dual-polarization techniques enhance the capabilities of optical devices.

Purpose of the Study:

• To investigate the dynamics of dual-polarization optical frequency combs (OFCs).
• To explore the use of gain switching (GS) VCSEL diodes with optical injection locking (OIL).
• To achieve controllable polarization states in OFCs.

Main Methods:

• Utilizing gain switching (GS) in vertical-cavity surface-emitting laser (VCSEL) diodes.
• Implementing optical injection locking (OIL) to control laser dynamics.
• Analyzing the polarization states and spectral properties of the generated OFCs.

Main Results:

• An overall OFC composed of two orthogonally polarized sub-combs with comparable span and power was achieved.
• The OFC exhibited enhanced optical span, flatness, and high mode coherence.
• Single-polarization OFCs (parallel or orthogonal) were generated by controlling the injected light's polarization.

Conclusions:

• Novel findings demonstrate efficient and compact dual-polarization OFCs based on GS VCSELs.
• Versatile polarization dynamics control is achievable by tuning the injected light's polarization.
• This work paves the way for advanced OFC applications requiring specific polarization characteristics.