Color-switching in an optical parametric oscillator using a phase-conjugate mirror

Area of Science:

• Nonlinear Optics
• Quantum Optics
• Laser Physics

Background:

• Phase-conjugate mirrors offer unique optical properties.
• Four-wave mixing (4WM) is a key nonlinear process for generating phase conjugation.
• Resonator design is critical for stable laser pulse generation.

Purpose of the Study:

• To construct a novel phase-conjugate resonator.
• To achieve stable, alternating probe and conjugate color pulses.
• To explore passive mode-locking and instability suppression.

Main Methods:

• Constructed a phase-conjugate resonator using non-degenerate four-wave mixing (4WM) in rubidium vapor.
• Employed a glancing-angle phase-conjugate mirror as a 100% output coupler.
• Operated an optical parametric oscillator above threshold for passive mode-locking.

Main Results:

• The resonator passively produced stable pulses alternating between probe and conjugate colors.
• The phase-conjugate mirror effectively suppressed thermal and acoustic instabilities (MHz timescale and slower).
• Demonstrated passive mode-locking in the formed optical parametric oscillator.

Conclusions:

• This work presents a new method for stable pulsing using phase-conjugate optics.
• The developed resonator serves as a platform for mode-locked pulses with squeezed light.
• The 4WM process's demonstrated quantum correlations support potential applications in quantum information.