The optical frequency comb fibre spectrometer

• Published in: Nature communications 2016-10, Vol.7 (1), p.12995-12995, Article 12995
• Main Authors: Coluccelli, Nicola, Cassinerio, Marco, Redding, Brandon, Cao, Hui, Laporta, Paolo, Galzerano, Gianluca
• Format: Article
• Language: English
• Subjects: 140/125; 639/624/1107/527/2257; 639/624/1111/1112; 639/624/1111/1116; Accuracy; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Spectrum analysis
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms12995

Optical frequency comb sources provide thousands of precise and accurate optical lines in a single device enabling the broadband and high-speed detection required in many applications. A main challenge is to parallelize the detection over the widest possible band while bringing the resolution to the single comb-line level. Here we propose a solution based on the combination of a frequency comb source and a fibre spectrometer, exploiting all-fibre technology. Our system allows for simultaneous measurement of 500 isolated comb lines over a span of 0.12 THz in a single acquisition; arbitrarily larger span are demonstrated (3,500 comb lines over 0.85 THz) by doing sequential acquisitions. The potential for precision measurements is proved by spectroscopy of acetylene at 1.53 μm. Being based on all-fibre technology, our system is inherently low-cost, lightweight and may lead to the development of a new class of broadband high-resolution spectrometers. An ideal optical frequency-comb system should combine both single-line spectral resolution and a bandwidth broad enough to cover as many lines as possible. Here, the authors incorporate a fibre spectrometer to detect approximately 500 comb-lines with an instrument resolution of 120 megahertz.