Effects of dispersion on mode locking in optical parametric oscillators

Area of Science:

• Nonlinear Optics
• Quantum Optics
• Laser Physics

Background:

• Synchronously pumped optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Understanding mode locking dynamics is essential for optimizing OPO performance and pulse characteristics.
• The interplay between dispersion and parametric gain in OPOs requires detailed investigation.

Purpose of the Study:

• To investigate the influence of group-velocity dispersion and cavity detuning on mode locking in synchronously pumped OPOs.
• To analyze the impact of phase-sensitive parametric gain on pulse structure and spectral properties.
• To elucidate the underlying physical mechanisms responsible for observed phenomena.

Main Methods:

• Theoretical analysis of mode locking in synchronously pumped OPOs.
• Consideration of group-velocity dispersion and cavity detuning effects.
• Phase-sensitive analysis of parametric gain in the degenerate OPO case.

Main Results:

• Dispersion effects, particularly during off-resonance operation, significantly impact mode locking onset.
• Subpulse structures and spectral splitting of parametric pulses are observed due to dispersion.
• These phenomena are attributed to dispersion-induced interference between nearly degenerate parametric photons.

Conclusions:

• Group-velocity dispersion and cavity detuning are critical parameters governing mode locking in synchronously pumped OPOs.
• Dispersion-induced interference offers a new perspective on spectral splitting and subpulse formation in parametric processes.
• The findings provide insights into controlling ultrashort pulse generation in nonlinear optical systems.