Abstract
Terahertz dual frequency comb spectroscopy (THz-DFCS) yields high spectral resolution without compromising bandwidth. Nonetheless, the resolution of THz-DFCS is usually limited by the laser repetition rate, which is typically between 80 MHz and 1 GHz. In this paper, we demonstrate a new method to achieve sub-repetition rate resolution in THz-DFCS by adaptively modifying the effective laser repetition rate using integrated Mach-Zehnder electro-optic modulators (MZ-EOMs). Our results demonstrate that it is possible to improve the 100 MHz resolution of a terahertz frequency comb by at least 20x (down to 5 MHz) across the terahertz spectrum without compromising the average output power, and to a large extent, its bandwidth. Our approach can augment a wide range of existing THz-DFCS systems to provide a significant and easily adaptable resolution improvement.
| Original language | English |
|---|---|
| Pages (from-to) | 30100-30107 |
| Journal | Optics Express |
| Volume | 24 |
| Issue number | 26 |
| DOIs | |
| Publication status | Published - 26 Dec 2016 |
| MoE publication type | A1 Journal article-refereed |
Funding
National Institute of Standards and Technology (NIST) Greenhouse Gas and Climate Science Measurements; DARPA SCOUT Program; Fundação de Amparo à Pesquisa no Estado de São Paulo (FAPESP); (2014/10125-8, 2011/13777-8, 2013/19093-9, 2008/57857-2); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); (229211/2013-5, 574017/2008); This paper is a contribution of the US government and is not subject to copyright in the US.