# Improved laser based photoluminescence on single-walled carbon nanotubes

## TL;DR

This paper introduces an improved dye-laser system based on a Q-switch pump laser that provides high-intensity, tunable, and time-resolved excitation for enhanced photoluminescence characterization of single-walled carbon nanotubes.

## Contribution

The authors develop a high-power, threshold-free dye laser system enabling more efficient and versatile excitation in PL studies of SWCNTs, covering a broad wavelength range with improved operability.

## Key findings

- Enhanced spectral intensity in PL measurements.
- Broader wavelength coverage (540-730 nm).
- Time-resolved laser pulses matching pump properties.

## Abstract

Photoluminescence (PL) has become a common tool to characterize various properties of single-walled carbon nanotube (SWCNT) chirality distribution and the level of tube individualization in SWCNT samples. Most PL studies employ conventional lamp light sources whose spectral distribution is filtered with a monochromator but this results in a still impure spectrum with a low spectral intensity. Tunable dye lasers offer a tunable light source which cover the desired excitation wavelength range with a high spectral intensity, but their operation is often cumbersome. Here, we present the design and properties of an improved dye-laser system which is based on a Q-switch pump laser. The high peak power of the pump provides an essentially threshold-free lasing of the dye laser which substantially improves the operability. It allows operation with laser dyes such as Rhodamin 110 and Pyridin 1, which are otherwise on the border of operation of our laser. Our system allows to cover the 540-730 nm wavelength range with 4 dyes. In addition, the dye laser output pulses closely follow the properties of the pump this it directly provides a time resolved and tunable laser source. We demonstrate the performance of the system by measuring the photoluminescence map of a HiPco single-walled carbon nanotubes sample.