SpectraPlot.com: Integrated spectroscopic modeling of atomic and molecular gases

Abstract

SpectraPlot is a web-based application for simulating spectra of atomic and molecular gases. At the time this manuscript was written, SpectraPlot consisted of four primary tools for calculating: 1) atomic and molecular absorption spectra, 2) atomic and molecular emission spectra, 3) transition linestrengths, and 4) blackbody emission spectra. These tools currently employ the NIST ASD, HITRAN2012, and HITEMP2010 databases to perform line-by-line simulations of spectra. Spec-traPlot employs a modular, integrated architecture, enabling multiple simulations across multiple databases and/or thermodynamic conditions to be visualized in a single interactive plot window. The primary objective of this paper is to describe the architecture and spectroscopic models employed by SpectraPlot in order to provide its users with the knowledge required to understand the capabilities and limitations of simulations performed using SpectraPlot. Further, this manuscript discusses the accuracy of several underlying approximations used to decrease computational time, namely, the use of far-wing cutoff criteria.

EXOCROSS: a general program for generating spectra from molecular line lists

“…The two-file format of the ExoMol database requires special structure for the broadening parameters. Instead of using the conventional line-by-line approach employed by spectroscopic databases such in HITRAN (Gordon et al 2017) or GEISA (Jacquinet-Husson et al 2016), where the pressure broadening are specified for the each transitions, ExoMol's broadening parameters are stored in separate files with the extension .broad ). This structure is justified for most applications as the same parameters are usually used for a large number of different transitions.…”

“…Other useful functionality include computing lifetimes , stick spectra, partition functions, cooling functions, and specific heats. The HI-TRAN molecular spectroscopic database (Gordon et al 2017) is a widely-used compilation aimed at radiative transport studies of the Earth's atmosphere. ExoCross is capable of working with HITRAN line lists (.par) as well as super-lines (Rey et al 2016;Yurchenko et al 2017a).…”

“…These include the HI-TRAN interface HAPI (Kochanov et al 2016), SpectraPlot.com (Goldenstein et al 2017) and SPECTRA (Tennyson et al 1993). …”

Ring resonator enhanced mode-hop-free wavelength tuning of an integrated extended-cavity laser

“…We demonstrate this small step size by recording the shape of an acetylene absorption line in high resolution. Acetylene ( 12 C2H2) is chosen because it has several well-known sharp absorption lines in the wavelength range of interest, which can be modelled with high accuracy [33,34]. For this experiment, we choose the P19 ro-vibrational absorption line of acetylene with a center wavelength of 1536.713 nm.…”

“…Figure 7 shows the measured normalized transmission through the gas cell as function of the calibrated wavelength of the laser (red dots). The calculated normalized transmission [33] for nominal pressure corresponding to the temperature of the absorption cell is shown as a blue line. We observe in Fig.…”