Quasi-phase-matched self-pumped optical parametric oscillation in a micro-resonator

Area of Science:

• Nonlinear Optics
• Materials Science
• Photonics

Background:

• Whispering-gallery-mode (WGM) micro-resonators offer high optical confinement.
• Neodymium-doped lithium niobate is a promising material for nonlinear optical applications.

Purpose of the Study:

• To demonstrate lasing and self-pumped optical parametric oscillation (self-OPO) in a single WGM micro-resonator.
• To investigate the performance of a quasi-phase-matched self-OPO in a micro-cavity.

Main Methods:

• Fabrication of a high-Q WGM micro-resonator from neodymium-doped lithium niobate.
• Utilizing a current-controlled calligraphic poling technique for radial quasi-phase-matching.
• Pumping the micro-resonator with a 1.08 μm laser to initiate lasing and self-OPO.

Main Results:

• Achieved lasing with 5 mW output power at 1.08 μm.
• Demonstrated self-OPO with combined signal and idler output power exceeding 1.2 mW at 6 mW pump power.
• Generated light across a wavelength range of 1.5 to 3.8 μm.

Conclusions:

• First demonstration of a quasi-phase-matched self-pumped nonlinear optical process in a micro-resonator.
• First demonstration of self-OPO in a micro-resonator.
• The developed concept shows potential for highly integrated, wavelength-tunable, low-cost coherent light sources.