Signal amplification and control in optical cavities with off-axis feedback

Area of Science:

• Photonics and Optical Engineering
• Nonlinear Optics
• Laser Physics

Background:

• Optical cavities and gain media are fundamental components in laser technology.
• External feedback mechanisms can significantly influence laser dynamics and output characteristics.
• Understanding nonlocality in optical systems is crucial for advanced light manipulation.

Purpose of the Study:

• To investigate the effects of off-axis external feedback on optical cavities and gain media.
• To explore the introduction and implications of two-point nonlocality.
• To demonstrate novel methods for controlling light propagation and amplification.

Main Methods:

• Modeling a large class of optical cavities and gain media.
• Introducing off-axis external feedback to create two-point nonlocality.
• Analyzing the impact of nonlocality on lasing thresholds and signal amplification.
• Investigating the independent tuning of transverse phase and group velocities.

Main Results:

• The introduced nonlocality modifies the lasing threshold.
• Large control parameter windows are identified for strong amplification of weak light spots with low background radiation.
• Independent tuning of transverse phase and group velocities is achieved.
• Demonstrated capabilities include non-mechanical steering, spatial chirp control, and signal splitting into counterpropagating beams.

Conclusions:

• Off-axis feedback provides a powerful tool for controlling laser behavior and light propagation.
• Two-point nonlocality offers new avenues for enhancing signal amplification and manipulating light.
• The ability to independently control transverse velocities opens possibilities for advanced optical functionalities.