Low temperature co-fired ceramics plasma generator for atmospheric pressure gas spectroscopy

Accurate and reliable measurements of gas composition are very important in science and industry applications. One way to accomplish this task is to measure spectrum of plasma gas discharge. In our work, we propose integrated microcell for optical measurements of gas discharge at atmospheric pressure. This device is fabricated using Low Temperature Co-fired Ceramics (LTCC) technology. Investigated gas is excited in buried air-cavity, placed between two electrodes. Discharge is created using high alternating voltage (30 kV). Optical signal is then transmitted through an integrated optical fibre to the miniature spectrometer. Because different gases have different emission lines, plot of light intensity vs. wavelength provides information about molecular composition of the investigated gas sample. In this work, design, fabrication and performance of the LTCC-based gas discharge chamber is presented. Spectral measurements are performed for air, argon and nitrogen. Moreover, influence of gas flow rate on obtained emission spectrum is discussed.