Messung der elektrischen Feldstärke in einer Gasentladung mittels Doppler-freier optogalvanischer Spektroskopie unter Verwendung von Laserdioden

A new highly-sensitive method for the detection of the local electric field strength in hydrogen discharges is presented in this Thesis. This method is ideally suited for systems with low electric field strength. Using the intermodulated optogalvanic spectroscopy, Doppler-free spectra of the first Balmer line of Hydrogen were taken in the cathode fall of a low pressure glow discharge. Once the theoretical splitting is known, the electric field strength can be determined from the position of the Doppler-free Stark components of the hydrogen Balmer alpha line. To obtain the electric field strength these profiles were fitted to the Doppler-free optogalvanic spectra. It has been shown for the first time that by using the Doppler-free intermodulated optogalvanic spectroscopy isolated Stark components may be measured. This novel technique is a key development for the investigation of low electric field strengths in low pressure glow discharges.