Control of the coherence behavior in a SFG interferometer through the multipump phases command.

Area of Science:

• Nonlinear optics
• Quantum optics
• Interferometry

Background:

• Sum frequency generation (SFG) is a key nonlinear optical process.
• Controlling coherence in interferometers with multiple independent light sources is challenging.
• Maximizing fringe contrast in SFG interferometers requires superposition of incoherent patterns.

Purpose of the Study:

• To develop a novel method for controlling coherence in a sum frequency generation interferometer.
• To enable superposition of incoherent fringe patterns for maximized contrast.
• To demonstrate experimental feasibility and scalability of the coherence control method.

Main Methods:

• Utilizing two independent pump laser lines in an SFG interferometer.
• Implementing differential group delay cancellation.
• Employing phase control on one pump line for fringe pattern synchronization.

Main Results:

• Successfully controlled coherence behavior in the SFG interferometer.
• Achieved superposition of incoherent fringe patterns, enhancing contrast.
• Experimentally validated the method using specific laser wavelengths (1544 nm signal, ~1064 nm pumps, ~630 nm converted signal).

Conclusions:

• The presented method effectively controls coherence in SFG interferometers.
• The technique is robust and can be extended to systems with more than two pump lines.
• This work advances the control of nonlinear optical processes for various applications.