Cost-effective time-stretch terahertz recorders using 1550 nm probes

TL;DR

This paper demonstrates a cost-effective time-stretch THz waveform recorder using standard 1550 nm probes and components, enabling high-sample recordings with low-bandwidth oscilloscopes.

Contribution

It introduces a novel, low-cost design for THz time-stretch detection that requires only standard components and modest bandwidth equipment.

Findings

Recorded coherent THz pulses at SOLEIL facility with low-bandwidth oscilloscopes.

Achieved high sample counts without high-speed ADCs or oscilloscopes.

Utilized standard 1550 nm probes and dispersive devices for cost reduction.

Abstract

Time-stretch electro-optic detection allows THz waveforms to be recorded in single-shot, up to Megahertz acquisition rates. This capability is required in accelerator physics, and also opens new applications in table-top THz time-domain spectroscopy. However, the technique has also been notoriously known for the need of high speed -- and high cost -- ADCs or oscilloscopes for the readout. Furthermore, the resulting cost considerably increases with the number of samples that is needed per THz waveform, an issue that has severely limited the widespread of the technique so far. In this article, we show that particularly cost-effective designs can be obtained by using 1550~nm probes. We present the performances of an experimental design, that uses only standard components (including dispersive devices), and a standard commercial probe laser without additional pulse broadening. In these conditions, our time-stretch system could already record coherent THz pulses at the SOLEIL synchrotron radiation facility, over an unprecedented number of samples, using oscilloscopes and ADC boards with only 1-3 GHz bandwidth.