Near-Infrared Laser Spectrometer with Sub-Doppler Resolution, High Sensitivity, and Wide Tunability: A Case Study in the 1.65-μm Region of CH3I Spectrum

Ishibashi, Chikako; Sasada, Hiroyuki

doi:10.1006/jmsp.1999.8031

Cited by 20 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While that first realization was based on a fixed frequency Nd:YAG laser, there have been several attempts since then to make use of the extreme sensitivity by the development of instrumentations based on various types of tunable lasers [4][5][6][7][8][9][10][11][12][13]. The so far best Db detection sensitivity incorporating a tunable laser was recently demonstrated with a fiber-laser-based (FLB) NICE-OHMS system, yielding an Allan deviation of 5.6 × 10 −12 cm −1 Hz −1∕2 , which for an integration time of 10 s corresponds to 4 ppt of acetylene in an atmospheric pressure sample [14].…”

Section: Introductionmentioning

confidence: 99%

Doppler broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry: optimum modulation and demodulation conditions, cavity length, and modulation order

2014

View full text Add to dashboard Cite

Doppler broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry (Db-NICE-OHMS) has been scrutinized with respect to modulation and demodulation conditions (encompassing the modulation frequency, ν m , the modulation index, β, and the detection phase, θ), the cavity length, L, and the modulation order, k (defined as ν m ∕ν FSR , where ν FSR is the free-spectral range of the cavity), primarily in the Doppler limit but also for two specific situations in the Voigt regime (for equal Doppler and homogeneous width and for purely Lorentzian broadened transitions), both in the absence and presence of optical saturation (the latter for the case in which the homogeneous broadening is smaller than the modulation frequency). It is found that, for a system with a given cavity length, the optimum conditions (i.e., those that produce the largest NICE-OHMS signal) for an unsaturated transition in the Doppler limit comprise ν m ∕Γ D 1.6 (where Γ D is the half-width at half-maximum of the Doppler width of the transition), β 1.3, and θ 0.78π. It is also found that the maximum is rather broad; the signal takes 95% of its maximum value for modulation frequencies in the entire 0.4 ≲ ν m ∕Γ D ≲ 2.4 range. When optical saturation sets in, θ shifts toward the dispersion phase. The optimum conditions encompass k > 1 whenever L > 0.35L D and 2.6L D for the dispersion and absorption modes of detection, respectively [where L D is a characteristic length given by c∕2Γ D ]. Similar conditions are found under pressure broadened conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Doppler broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry: optimum modulation and demodulation conditions, cavity length, and modulation order

2014

View full text Add to dashboard Cite

show abstract

“…Since its earliest realizations, the NICE-OHMS technique has mainly been developed around various types of tunable lasers. To expand its applicability to trace gas detection, it has predominately addressed Db transitions ; it has only occasionally been utilized for sD detection, then for other purposes [20,[56][57][58][59][60]. Among the latter realizations, a white noise limited detection sensitivity of 5 × 10 -11 cm -1 Hz -1/2 has been reported [57].…”

Section: Introductionmentioning

confidence: 99%

High-resolution trace gas detection by sub-Doppler noise-immune cavity-enhanced optical heterodyne molecular spectrometry: application to detection of acetylene in human breath

et al. 2019

View full text Add to dashboard Cite

A sensitive high resolution sub-Doppler detecting spectrometer, based on noiseimmune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS), for trace gas detection of species whose transitions have severe spectral overlap with abundant concomitant species is presented. It is designed around a NICE-OHMS instrumentation utilizing balanced detection that provides shot-noise limited Doppler-broadened detection. By synchronous dithering the positions of the two cavity mirrors, the effect of residual etalons between the cavity and other surface in the system could be reduced. An Allan deviation of the absorption coefficient of 2.2 × 10 -13 cm -1 at 60 s, which, for the targeted transition in C2H2, corresponds to a 3σ detection sensitivity of 130 ppt, is demonstrated. It is shown that despite significant spectral interference from CO2 at the targeted transition, which precludes Db detection of C2H2, acetylene could be detected in exhaled breath of healthy smokers.

show abstract

“…A variety of tunable lasers, including an external cavity diode laser (ECDL) (Bell et al, 2009;Chen and Liu, 2015;Dinesan et al, 2014;Ishibashi and Sasada, 2000;Saraf et al, 2016;van Leeuwen and Wilson, 2004), quantum cascade laser (QCL) (Taubman et al, 2004), optical parametric oscillator (OPO) (Hausmaninger et al, 2015;Talicska et al, 2016;Taubman et al, 2004), quantum-dot laser (Chen and Liu, 2017), distributed feedback laser (DFB) (Foltynow-icz et al, 2010) and whispering-gallery-mode (WGM) laser (Zhao et al, 2017), have been applied to the NICE-OHMS system over the years. The most persistent development of NICE-OHMS has been performed based on erbium-doped fiber lasers (EDFLs), which lase in the near-IR (NIR) region (Ehlers et al, 2012;Schmidt et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Laser frequency stabilization based on a universal sub-Doppler NICE-OHMS instrumentation for the potential application in atmospheric lidar

et al. 2019

View full text Add to dashboard Cite

Abstract. Lidar is an effective tool for high-altitude atmospheric measurement in which a weak absorption line for the target gas is selected to ensure a large optical depth. The laser frequency stabilization to the line center is required, and a sub-Doppler (sD) spectroscopy of the target line is preferred as a frequency reference. In this paper, a novel universal sD noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) instrumentation based on a fiber-coupled optical single-sideband electro-optic modulator (f-SSM) for the potential application in atmospheric lidar for different target gases with different types of lasers is reported. The f-SSM can replace all frequency actuators in the system, so as to eliminate the individual design of feedback servos that often are tailored for each laser. The universality of the instrumentation was demonstrated by the alternative use of either an Er-doped fiber laser or a whispering-gallery-mode laser. Then the instruments based on both lasers were used to produce the sD signals of acetylene, which worked as a frequency reference to stabilize the laser. By performing the lockings, relative frequency stabilizations of 8.3×10-13 and 7.5×10-13 at an integration time of 240 s were demonstrated.

show abstract

Near-Infrared Laser Spectrometer with Sub-Doppler Resolution, High Sensitivity, and Wide Tunability: A Case Study in the 1.65-μm Region of CH3I Spectrum

Cited by 20 publications

References 16 publications

Doppler broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry: optimum modulation and demodulation conditions, cavity length, and modulation order

Doppler broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry: optimum modulation and demodulation conditions, cavity length, and modulation order

High-resolution trace gas detection by sub-Doppler noise-immune cavity-enhanced optical heterodyne molecular spectrometry: application to detection of acetylene in human breath

Laser frequency stabilization based on a universal sub-Doppler NICE-OHMS instrumentation for the potential application in atmospheric lidar

Contact Info

Product

Resources

About