Dual-band Fabry-Perot lasing from single ZnO microbelt

•The lasing performance, spectral variation and mode structure significantly depended on the cavity size.•The mode spacing is inversely proportional to the ZnO microbelt size.•The light distribution in the ZnO microbelt cavity is numerically simulated by FDTD method.

Dual-band semiconductor microbelt lasing are promising for multifunctional applications ranging from optical communication to spectroscopy analysis. Here, we demonstrated a dual-band Fabry-Perot (F-P) lasing from both length and width directions in a single ZnO microbelt. The lasing performance, spectral variation and mode structure significantly depended on the cavity size, which corresponded to the length and width of the ZnO microbelts. The resonant process and mechanism were investigated systematically through the experimental analysis and numerically FDTD simulation. The results of the dual-band F-P lasing modes and wide lasing wavelength are helpful to design the dual-wavelength electronic and optoelectronic devices.