Direct Absorption and Photoacoustic Spectroscopy for Gas Sensing and Analysis: A Critical Review

Laser & Photonics Review, Journal Year: 2022, Volume and Issue: 16(8)

Published: May 10, 2022

Abstract Optical spectroscopy has a broad scientific basis in chemistry, physics, and material science, with diverse applications medicine, pharmaceuticals, agriculture, environmental monitoring. Fourier transform infrared (FTIR) spectrometers tunable laser (TLS) are key devices for measuring optical spectra. Superior performance terms of sensitivity, selectivity, accuracy, resolution is required gas sensing. This review deals measurement based on either direct absorption or photoacoustic spectroscopy. Both approaches applicable to FTIR TLS. In spectroscopy, cantilever‐based focused due its high performance. A literature survey conducted revealing the recent technological advances. Theoretical fundamental detection limits derived TLS FTIR, considering both spectroscopies. theoretical comparison reveals which technology performs better. The minimum normalized coefficient noise equivalent appear as parameters this comparison. For TLS‐based systems, found be best lower power longer path length. FTIR‐based low temperature sources, higher spectrometer throughput, faster mirror velocity, cells.

Language: Английский

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Broadband near-ultraviolet dual comb spectroscopy

Optica, Journal Year: 2024, Volume and Issue: 11(4), P. 471 - 471

Published: March 5, 2024

The highly energetic photons of ultraviolet light drive electronic and rovibronic transitions in all molecular species. This radiation is thus a prime tool for strongly selective spectroscopic fingerprinting real-time environmental monitoring if broad spectral coverage, short acquisition times, high resolution are achieved–requirements that mutual competition traditional applications. As an approach with intrinsic potency three aspects, here we introduce dual comb spectroscopy using two broadband frequency combs centered at 871 THz covering bandwidth 35.7 THz. Within 100 µs time window, obtain rotational state-resolved absorption spectra formaldehyde, prototype molecule relevance laser sciences. To our knowledge, this the first realization region pioneering to allow transitions.

Language: Английский

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Compact mid-infrared dual-comb spectrometer over 3–4 μm via intra-pulse difference frequency generation in LiNbO₃ waveguides

High Power Laser Science and Engineering, Journal Year: 2024, Volume and Issue: 12

Published: Jan. 1, 2024

Abstract The mid-infrared optical frequency comb is a powerful tool for gas sensing. In this study, we demonstrate simple dual-comb spectrometer covering 3–4 μm in LiNbO 3 waveguides. Based on low-power fiber laser system, the achieved via intra-pulse difference generation waveguide. We construct pre-chirp management before supercontinuum to control spatiotemporal alignment pump and signal pulses. directly coupled into chirped periodically poled waveguide idler generation. A based approach provides 100 MHz resolution over 25 THz coverage. To evaluate applicability spectroscopy, measure methane spectrum using spectrometer. measured results are consistent with HITRAN database, which root mean square of residual 3.2%. This proposed method expected develop integrated robust spectrometers chip

Language: Английский

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Ultra-broadband spectroscopy using a 2–11.5 µm IDFG-based supercontinuum source

Optics Express, Journal Year: 2024, Volume and Issue: 32(8), P. 14506 - 14506

Published: Feb. 12, 2024

Supercontinuum sources based on intrapulse difference frequency generation (IDFG) from mode-locked lasers open new opportunities in mid-infrared gas spectroscopy. These provide high power and ultra-broadband spectral coverage the molecular fingerprint region with very low relative intensity noise. Here, we demonstrate performance of such a light source combination multipass cell custom-built Fourier transform spectrometer (FTS) for multispecies trace detection. The provides low-noise, ultra-broad spectrum 2–11.5 µm ∼3 W output power, outperforming existing supercontinuum terms noise, coverage, power. This translates to an excellent match spectroscopic applications, establishing (sub-)ppb sensitivity hydrocarbons (e.g., CH 4 , C 2 H ), oxides SO NO x small organic molecules acetone, ethyl acetate) over range measurement time varying seconds minutes. We practical application by measuring off-gas composition bioreactor containing acidic ammonia-oxidizing culture simultaneous detection multiple nitrogen (NO, N O, etc.). As different species absorb various parts spectrum, these results highlight functionality this system biological environmental applications.

Language: Английский

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Open‐Path Dual‐Comb Spectroscopy for Multispecies Trace Gas Detection in the 4.5–5 µm Spectral Region

Laser & Photonics Review, Journal Year: 2021, Volume and Issue: 15(9)

Published: June 30, 2021

Abstract Open‐path dual‐comb spectroscopy provides multispecies atmospheric gas concentration measurements with high precision. Here, open‐path is extended to the mid‐infrared 5 µm window, enabling retrievals of primary greenhouse gases, N 2 O, CO , and H as well criteria air pollutants O 3 across 600 m km round‐trip paths. Measurements are demonstrated over a five‐day period at min temporal resolution 80% uptime. The achieved precision sufficient resolve variations multiple species; retrieved dry mixing ratios in good agreement colocated point sensor. In addition, ratio excess versus agrees similar urban studies but disagrees US National Emission Inventory by factor 3. exhibits plume‐dependent value, indicating variability sources O.

Language: Английский

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High-SNR mid-infrared dual-comb spectroscopy using active phase control cooperating with CWs-dependent phase correction

Optics Express, Journal Year: 2024, Volume and Issue: 32(4), P. 5826 - 5826

Published: Jan. 24, 2024

Mid-infrared (MIR) dual-comb spectroscopy (DCS) is a highly effective method for molecular metrology of rovibrational transition spectra in quick accurate manner. However, due to limited comb frequency instability, manipulating coherence between two combs accomplish high-quality spectral analysis the MIR region huge challenge. Here, we developed comb-teeth resolved DCS based on active phase control cooperating with CWs-dependent (CWD) interferogram timing correction. Firstly, four meticulously engineered actuators were individually integrated into near-infrared (NIR) seed facilitate maintenance. Subsequently, PPLN waveguides adopted achieve parallel difference generations (DFG), directly achieving coherent spectrometer. To improve and signal-to-noise ratio (SNR), CWD resampled correction was used optimize merit from 7.5 × 10 5 2.5 6 . Meanwhile, carried out measurement methane hot-band absorption ( v 3 band), which exhibited good agreement HITRAN by standard deviation recording residual 0.76%. These experimental results confirm that this has significant potential characterize transitions molecules.

Language: Английский

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Dual-comb spectroscopy over a 100 km open-air path

Nature Photonics, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 12, 2024

Language: Английский

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Miniature optical fiber photoacoustic spectroscopy gas sensor based on a 3D micro-printed planar-spiral spring optomechanical resonator

Photoacoustics, Journal Year: 2024, Volume and Issue: 40, P. 100657 - 100657

Published: Oct. 24, 2024

Language: Английский

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Single-cycle all-fiber frequency comb

APL Photonics, Journal Year: 2021, Volume and Issue: 6(8), P. 086110 - 086110

Published: Aug. 1, 2021

Single-cycle pulses with a deterministic carrier-envelope phase enable the study and control of light–matter interactions at sub-cycle timescale, as well efficient generation low-noise multi-octave frequency combs. However, current single-cycle light sources are difficult to implement operate, hindering their application accessibility in wider range research. In this paper, we present 100 MHz comb compact, turnkey, reliable all-silica-fiber format. This is achieved by amplifying 2 µm seed heavily doped Tm:fiber, followed cascaded self-compression yield 6.8 fs 215 kW peak power 374 mW average power. The corresponding spectrum covers more than two octaves, from below 700 up 3500 nm. Driven pump, supercontinuum 180 integrated smooth spectral amplitude between 2100 2700 nm generated directly silica fibers. To broaden applications, few-cycle extending 6 beyond 22 long-term stable created using intra-pulse difference frequency, electro-optic sampling yields comb-tooth-resolved spectra. Our work demonstrates first all-fiber configuration that generates provides practical source nonlinear optics on same timescale.

Language: Английский

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Dual-comb quartz-enhanced photoacoustic spectroscopy

Photoacoustics, Journal Year: 2022, Volume and Issue: 28, P. 100403 - 100403

Published: Sept. 21, 2022

Photoacoustic spectroscopy (PAS) using two optical combs is a new-born technique, offering appealing features, including broad bandwidths, high resolutions, fast acquisition speeds, and wavelength-independent photoacoustic detection, for chemical sensing. However, its further application to, e.g., trace jeopardized due to the fundamentally technically limited sensitivity specificity. Here, we take different route comb-enabled PAS with acoustically enhanced nonlinear spectral hole-burning defined resolution. We demonstrate dual-comb quartz-enhanced near-infrared electro-optic quartz tuning fork. Comb-line-resolved multiplexed spectra are acquired acetylene single-pass detection limit at parts-per-billion level. The technique extended mid-infrared (for methane), enabling improved sensitivity. More importantly, measure

Language: Английский

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