Two-micron all-fibered dual-comb spectrometer based on electro-optic modulators and wavelength conversion

Abstract

Mid-infrared dual-comb spectroscopy offers interesting applications since molecules have their strongest rotational–vibrational absorptions in this frequency domain. Besides, generating frequency combs with electro-optic modulators recently showed promising results toward dual-comb spectroscopy. Here, we report a conversion in the mid-infrared of two mutually coherent frequency combs generated with electro-optic modulators to perform dual-comb spectroscopy in this region. Using fourth-order modulation instability taking place in the normal dispersion regime of a highly nonlinear fiber and by seeding this phenomenon with a frequency agile and low-power laser around 1.3 μm, we develop a stable and wavelength tunable all-fibered dual-comb spectrometer operating in the 2 μm region. This allows us to investigate CO2 absorption spectra over 37 nm and to measure collisional broadening coefficients of a few rotational–vibrational lines.

Review of tellurite glasses purification issues for mid‐IR optical fiber applications

“…Such tellurite fibers exhibit an infrared supercontinuum extending from 1 µm up to 5 µm. This opens up new possibilities for applications of tellurite fibers such as absorption spectroscopy 89 , frequency comb generation for high resolution spectroscopy [90][91][92] , optical coherence tomography 93,94 , food quality analysis 95 , biomedical endoscopy [96][97][98][99] and atmospheric gas sensing. 81,100 9 List of tables L.mol -1 .cm - 1 37, 36 .…”

Comparative analysis of stimulated Brillouin scattering at 2 µm in various infrared glass-based optical fibers

“…In recent years, the 2-µm spectral window has been extensively exploited in order to design and develop devices and components for several applications such as high-resolution molecular sensing, frequency conversion, imaging, and bio-photonics, lasers and telecommunication systems [1][2][3][4][5][6][7]. Such developments have mainly benefited from the emergence of thuliumdoped fiber amplifiers (TDFA) that can amplify a broad spectral range around 2 µm.…”

High-power frequency comb at 2 μm wavelength emitted by a Tm-doped fiber laser system

“…Frequency combs at around 2 μm wavelength are currently of tremendous interest for next-generation spectroscopy targeting sensitive detection of certain gases (e.g., CO 2 , NH 3 ) [14,15] and/or to further extend the wavelength coverage of frequency combs to the molecular fingerprint region (3-20 μm) via parametric downconversion in nonlinear crystals [16,17]. With only very few exceptions [18,19], nonlinear crystals with high transmission in the mid-IR (>5 μm) are opaque at around 1 μm wavelength or high-power operation is severely limited by multiphoton absorption, exactly where the most powerful driving lasers operate [20].…”