Gate-controlled generation of optical pulse trains using individual carbon nanotubes

TL;DR

This paper demonstrates a method to generate optical pulse trains from individual carbon nanotubes by applying gate voltages, enabling controlled and synchronized optical pulses with adjustable timing.

Contribution

It introduces a novel technique for optical pulse train generation using electrostatic gating of single carbon nanotubes, with real-time control over pulse timing and duration.

Findings

Pulse trains are generated from individual nanotubes under gate voltage modulation.

Photoluminescence recovery frequency increases with laser power.

Time-resolved measurements confirm synchronized optical pulses.

Abstract

We report on optical pulse-train generation from individual air-suspended carbon nanotubes under an application of square-wave gate voltages. Electrostatically-induced carrier accummulation quenches photoluminescence, while a voltage sign reversal purges those carriers, resetting the nanotubes to become luminescent temporarily. Frequency domain measurements reveal photoluminescence recovery with characteristic frequencies that increase with excitation laser power, showing that photoexcited carriers quench the emission in a self-limiting manner. Time-resolved measurements directly confirm the presence of an optical pulse train sychronized to the gate voltage signal, and flexible control over pulse timing and duration is demonstrated.