Conformable nanowire-in-nanofiber hybrids for low-threshold optical gain in the ultraviolet

TL;DR

This paper introduces flexible ZnO nanowire-in-fiber hybrids that demonstrate low-threshold optical gain and polarized emission, suitable for miniaturized, conformable optical devices in bioimaging, sensors, and laser applications.

Contribution

The work presents a novel nanowire-in-fiber hybrid architecture with internal order, enabling low-threshold optical gain and mechanical flexibility not achieved in previous designs.

Findings

Demonstrated polarized stimulated emission in hybrids

Achieved lower threshold for amplified spontaneous emission than films

Confirmed high flexibility and conformability of the system

Abstract

The miniaturization of diagnostic devices that exploit optical detection schemes requires the design of light-sources combining small size, high performance for effective excitation of chromophores, and mechanical flexibility for easy coupling to components with complex and non-planar shapes. Here, ZnO nanowire-in-fiber hybrids with internal architectural order are introduced, exhibiting a combination of polarized stimulated emission, low propagation losses of light modes, and structural flexibility. Ultrafast transient absorption experiments on the electrospun material show optical gain which gives rise to amplified spontaneous emission, with threshold lower than the value found in films. These systems are highly flexible and can conveniently conform to curved surfaces, which makes them appealing active elements for various device platforms, such as bendable lasers, optical networks and sensors, as well as for application in bioimaging, photo-crosslinking, and optogenetics.