Multicolour wavelength-tunable lasing from a single bandgap-graded alloy nanoribbon

TL;DR

This paper demonstrates tunable multicolour lasing from a single bandgap-graded alloy nanoribbon, achieved by selective excitation and localized cavity formation, enabling room-temperature multicolour lasing.

Contribution

It introduces a novel method for multicolour lasing from a single nanoribbon using bandgap grading and localized cavities, overcoming reabsorption issues.

Findings

Lasing wavelength tunable from 578 nm to 640 nm.

Multicolour lasing observed simultaneously from the same nanoribbon.

Localized cavities enable lasing despite reabsorption challenges.

Abstract

Tunable lasing from 578 nm to 640 nm is observed from a single CdSSe bandgap-graded alloy nanoribbon, by selecting the excited spot at room temperature. Though reabsorption is a serious problem to achieve lasing at short wavelength, multiple scatters on the nanoribbon form localized cavities, and thus realize lasing at different wavelengths. By increasing the excitation area, we also observe multicolour lasing from the same nanoribbon simultaneously.