Cascaded optical parameter oscillator within lithium tantalate microdisk based on two periodically poled structures

The whispering gallery resonator (WGR) represents a promising avenue for the miniaturization of optical devices, while cascaded optical parameter oscillator (OPO) processes have not been realized in the WGR, to the best of our knowledge.We present a microdisk with quality factors up to 3.2 10 7 , then embed two quasi-phase-matching structures inside it to demonstrate cascaded OPO.The cascaded OPO exhibits the same idler light output with the threshold of 32.7 mW at 36C (1063.8nm 1566.6 nm + 3314.6 nm/1566.6 nm 2970.4 nm + 3314.6 nm), while the operating threshold of OPO without cascade process is 4.32 mW.Moreover, diverse cascaded processes are observed, with the longest output wavelength reaching 4802.9 nm.Our results suggest the potential for a low-threshold cascade OPO based on WGR.