The demand for miniaturization and integration of photonic devices, such as micro-nano lasers, has promoted the development of optical integrated systems.

In recent years, halide perovskite nanostructures have had significant advances and have opened up a bright future for micro/nano lasers. However, upconversion lasing by two-photon excitation with mode selection and high-quality factor in one device is still rarely reported.

A collaborative research team led by Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences (CAS) and Chongqing University has succeeded in obtaining stable and high-quality upconversion lasing from perovskite CsPb₂Br₅ microplates based on two kinds of microcavity effects. The results, entitled “Mode selection and high-quality upconversion lasing from perovskite CsPb₂Br₅ microplates”, were published in Photonics Research.

In the research of this team, they used the improved solution process to synthesize the subwavelength thickness and uniform square shape perovskite CsPb₂Br₅ microplates with average length ~4 μm. The regular morphology could form the natural microcavity structure. To investigate the gain property, the transient absorption spectroscopy was adopted to track the gain dynamics.

It was found that the net optical gain was established rapidly in less than 1 ps and lasts more than 30 ps, which would boost the effective buildup of population inversion. Subsequently, temperature-dependent amplified spontaneous emission (ASE) was observed with low threshold and high characteristic temperature of 403 K.

They found that the frequency-upconverted lasing with low thresholds (~230 and ~180 μJ/cm²) and high-quality factors (~3551 and ~3374) operating in Fabry–Pérot between two facets and whispering-gallery-mode (WGM) among the four corners by total internal reflection were demonstrated from a pristine CsPb₂Br₅ microplate at room temperature, respectively. The obtained quality factors were among the best values obtained from perovskite micro/nanoplate upconversion lasers. Moreover, the highly stable chromaticity with color drifts only less than 0.1 nm outbalanced the all-inorganic CsPbBr₃ ones.

All these findings suggest that perovskite CsPb₂Br₅ microplates will provide versatile opportunities and stable platforms for the exploration of nonlinear nanophotonic integrated devices.

This work was supported by the Strategic Priority Research Program of CAS and the National Natural Science Foundation of China.

WGM single-mode lasing characterization of a single CsPb₂Br₅ microplate under two-photon excitation. (Image by SIOM)

Article website:
https://www.osapublishing.org/prj/abstract.cfm?doi=10.1364/PRJ.399960

Contact:
Mr. Wu Xiufeng
General Administrative Office
Shanghai Institute of Optics and Fine Mechanics, CAS
Email: xfwu@siom.ac.cn