Compact Terahertz Dual‐Comb Spectroscopy with All‐Digitally Generated Adaptive Clock

This is the authors' abstract. We don't add key points for this paper.

Terahertz (THz) dual‐comb spectroscopy has been revolutionized by adaptive sampling, which enhances measurement precision and relaxes the requirement for ultra‐stable lasers. However, conventional adaptive clock schemes, reliant on analog electronics, are limited by bandwidth and inherent electronic/thermal noise. To overcome these limitations, we introduce a fully digital adaptive clock implemented on a field‐programmable gate array platform. Following time correction in sampling, we achieved a THz dual‐comb spectroscopy system spanning 1.6 THz with 24,191 resolved comb lines and a uniform spacing of 66.14 MHz. Our system demonstrates remarkable pulse‐period stability (1.15 × 10 −10 at 32 s integration time) and a comb‐line resolution at the kHz level. This all‐digital solution replaces complicated analog circuitry with a compact and reconfigurable digital architecture, enabling portable, high‐precision THz spectrometers capable of real‐time molecular fingerprints in field applications while maintaining laboratory‐grade accuracy.