Phase locking counterrotating modes of a broadband ring dye laser

Area of Science:

• Laser Physics
• Nonlinear Optics
• Quantum Optics

Background:

• Continuous-wave broadband ring dye lasers support counterrotating modes.
• Phase locking of these modes is crucial for various applications.
• Different coupling geometries can influence mode locking efficiency.

Purpose of the Study:

• To experimentally investigate phase locking of counterrotating modes in a Rhodamine-6G dye laser.
• To compare the effectiveness of different coupling geometries for achieving phase locking.
• To quantify the mutual coherence of the counterrotating fields under varying coupling conditions.

Main Methods:

• Experimental setup using a Rhodamine-6G continuous-wave broadband ring dye laser.
• Implementation of three distinct coupling geometries: intracavity retroreflector, single extracavity retroreflector, and dual extracavity retroreflectors.
• Measurement of mutual coherence between the counterrotating fields using interferometric techniques.

Main Results:

• The intracavity retroreflector geometry yielded the highest degree of phase locking.
• Counterrotating outputs exhibited a measured mutual coherence of unity with intracavity coupling.
• Extracavity coupling methods showed lower degrees of phase locking compared to the intracavity method.

Conclusions:

• Intracavity coupling is the most effective method for achieving high-fidelity phase locking of counterrotating modes in this laser system.
• A mutual coherence of unity signifies complete phase synchronization between the counterrotating fields.
• The findings have implications for controlling and utilizing complex laser dynamics.