Stripline split-ring resonator with integrated optogalvanic sample cell

Abstract

Stripline split-ring resonator with integrated optogalvanic sample cell.Laser Physics Letters, 11(4) dating and pharmaceutical sciences. However, recent reports show that ICOGS suffers from substantial problems with reproducibility. To qualify ICOGS as an analytical method, more stable and reliable plasma generation and signal detection are needed. In our proposed setup, critical parameters have been improved. We have utilized a stripline split-ring resonator microwave-induced microplasma source to excite and sustain the plasma. Such a microplasma source offers several advantages over conventional ICOGS plasma sources. For example, the stripline split-ring resonator concept employs separated plasma generation and signal detection, which enables sensitive detection at stable plasma conditions. The concept also permits in situ observation of the discharge conditions, which was found to improve reproducibility. Unique to the stripline split-ring resonator microplasma source of in this study, is that the optogalvanic sample cell has been embedded in the device itself. This integration enabled improved temperature control and more stable and accurate signal detection. Significant improvements are demonstrated, including reproducibility, signal-to-noise ratio and precision.

Improved optogalvanic detection with voltage biased Langmuir probes

“…2, was almost identical to the one in [16], having a 2 mm wide gap and a resonance frequency of 2.7 GHz, although the windows were replaced by ½ inch antireflection coated ZnSe windows (WG70530-F, Thorlabs Inc., Newton, NJ, USA) glued to two ½ inch union tee fittings (SS-8-UT-3, Swagelok, Solon, OH, USA), which served as gas connectors, instead of the integrated channels. The electronics, gas handling system, and optics of the setup too resembled that of [16], where the laser beam from a single longitudinal mode 12 CO 2 laser was modulated by a chopper before being coupled through the reference and SSRR cells to a power meter. However, there were a few differences compared with the earlier setup, Fig.…”

“…Previous studies [16] have shown that these approximations are valid in the typical operational region of the SSRR, where T e /T e ≈U P /U P ≈ 1/25 (hc  ≈0.12 eV for =10.59 µm). Finally, the relationship between U OG…”

“…Firstly, at its peak, OG detection often showed to be more sensitive than absorption measurements [15]. Although absorption detectors have evolved far since then, modern OG detectors, based on more stable and reliable technology, have demonstrated fast evolution and promising performance [16][17][18]. Secondly, and most interestingly, the fundamental differences between OG and absorption detectors make new spectrometer designs possible.…”

“…In previous work, we have demonstrated the use of a miniaturized stripline split-ring resonator (SSRR) as an OG detector for CO 2 [16][17][18]. The SSRR detector has been shown to be both more sensitive and reliable than current competitors, combining high reproducibility [16] with electromagnetic robustness [17].…”

“…The SSRR detector has been shown to be both more sensitive and reliable than current competitors, combining high reproducibility [16] with electromagnetic robustness [17]. Moreover, the volume of the sample cell of the SSRR is less than 100 µl, enabling analysis of extremely small samples [18].…”