Dual-Comb Spectrometer Based on Gain-Switched Semiconductor Lasers and a Low-Cost Software-Defined Radio

Abstract

Dual-comb spectroscopy has become a topic of growing interest in recent years due to the advantages it offers in terms of frequency resolution, accuracy, acquisition speed, and signal-to-noise ratio, with respect to other existing spectroscopic techniques. In addition, its characteristic of mapping the optical frequencies into radio-frequency ranges opens up the possibility of using non-demanding digitizers. In this paper, we show that a low-cost software defined radio platform can be used as a receiver to obtain such signals accurately using a dual-comb spectrometer based on gain-switched semiconductor lasers. We compare its performance with that of a real-time digital oscilloscope, finding similar results for both digitizers. We measure an absorption line of a H 13 C 14 N cell and obtain that for an integration time of 1 s, the deviation obtained between the experimental data and the Voigt profile fitted to these data is around 0.97% using the low-cost digitizer while it is around 0.84% when using the high-end digitizer. The use of both technologies, semiconductor lasers and low-cost software defined radio platforms, can pave the way towards the development of cost-efficient dual-comb spectrometers.

A versatile, phase coherent data acquisition system based on software-defined radio for graphene nanomechanics

“…and smaller scale experiments about oscillator metrology [22], optoelectronics [23], magnetic resonance spectroscopy [24], and optical spectroscopy [25], where commercially available SDRs are used. The architecture of SDRs reflects the need for a radio system that is compact, immune to environmental change (such as filter response drifts caused by temperature changes), and whose modulation and demodulation stages are highly reconfigurable.…”

High-Density and Broad Band Optical Frequency Combs Generated by Pseudo-Random Phase Modulation of Optically Injected Gain-Switched Semiconductor Lasers

“…The approach allows to tackle important applications requiring very small line spacing. Among them, high-resolution dual comb spectroscopy has been proved to be attainable at reduced cost on both the generation and detection sides [7,20]. Although the linewidth of the injection laser seems to be the only fundamental limitation to the smallest line spacing that can be achieved by the combination of pulsed GS and optical injection, the fast reduction in power per line as line spacing decreases makes this approach impractical for line spacing below a few tens of MHz.…”

Ultrasonic vibration measurement using heterodyne interferometry and SDR phase meter

“…It can be used with readily -available low-cost external radio frequency hardware (RTL-SDR dongle) to create software-defi ned radios [13]. SDR implementations have been used in diff erent applications, such as cognitive radio [14], lowpower and cost transceivers [15], coherent radar systems [16], and dual-comb spectrometers [17].…”