Indirectly-seeded optical parametric generation in periodically poled lithium niobate

Area of Science:

• Nonlinear Optics
• Laser Physics
• Materials Science

Background:

• Optical Parametric Generation (OPG) is crucial for tunable light sources.
• Controlling the spectral bandwidth of OPG output is essential for many applications.
• Traditional seeding methods have limitations in flexibility and efficiency.

Purpose of the Study:

• To introduce a novel injection-seeding technique for OPG.
• To demonstrate bandwidth reduction of the generated signal wave.
• To explore seeding using sum-frequency mixing of pump and signal waves.

Main Methods:

• Utilizing periodically poled lithium niobate for OPG.
• Employing a sum-frequency mixing process for the seed wavelength.
• Using a pulsed laser as a seed source.
• Investigating quasi-phase-matching conditions for the sum-frequency process.

Main Results:

• Demonstrated successful seeding of pulsed OPG with a sum-frequency mixed wave.
• Achieved substantial bandwidth reduction of the signal wave.
• Showed effectiveness even when the sum-frequency process is not quasi-phase-matched.
• Confirmed significant bandwidth reduction with a low-power (15 mW) HeNe seed beam under quasi-phase-matching.

Conclusions:

• The novel seeding technique offers a flexible approach to control OPG output.
• This method enhances spectral purity of generated parametric waves.
• The technique is effective for both quasi-phase-matched and non-quasi-phase-matched sum-frequency processes.