Periodically poled lithium niobate monolithic nanosecond optical parametric oscillators and generators

Area of Science:

• Nonlinear Optics
• Materials Science
• Quantum Electronics

Background:

• Optical Parametric Oscillators (OPOs) are crucial for generating tunable laser light.
• Developing compact, efficient, and easily alignable OPO devices remains a key challenge.
• Periodically poled lithium niobate (PPLN) offers significant nonlinear optical properties.

Purpose of the Study:

• To fabricate and characterize monolithic periodically poled lithium niobate optical parametric oscillators (OPOs) and generators.
• To assess the performance of these devices regarding tunability, stability, efficiency, and alignment.
• To investigate and explain the effects of noncollinear phase matching on tuning bandwidth.

Main Methods:

• Fabrication of monolithic periodically poled lithium niobate (PPLN) structures.
• Characterization of OPO and optical parametric generator (OPG) performance.
• Pumping devices with 3.5-ns, 1.064-μm pulses.
• Utilizing crystal rotation for tuning via noncollinear phase matching.
• Measurement and analysis of bandwidth-broadening effects.

Main Results:

• Compact, monolithic OPO/OPG devices were successfully fabricated and aligned with ease.
• Widely tunable, nearly diffraction-limited, stable output pulses were achieved.
• Low oscillation thresholds and high conversion efficiencies were demonstrated.
• Broad tuning was achieved through crystal rotation using noncollinear phase matching.
• Bandwidth-broadening effects in the noncollinear geometry were measured and theoretically explained.

Conclusions:

• Monolithic PPLN OPOs and OPGs are practical, high-performance devices for tunable light generation.
• Noncollinear phase matching provides a versatile method for broad tuning in these compact systems.
• The demonstrated performance characteristics pave the way for advanced applications in nonlinear optics.