title: Broadband and low insertion loss Stark cell for microwave spectroscopy.
abstract: A groove guide cell for Stark modulation spectroscopy has been constructed and tested. This structure with quasi-unique mode propagation between two isolated plates is well adapted to application of a modulation voltage. The insertion losses are low (0.6 dB for a 3-m-long cell, and R band) and the cell is free of internal reflection. A metallic casing enclosing the plates acts as a shield against electrical interference, prevents low-voltage breakdown, and reduces wall adsorption of the gas. The performance of the cell is not affected by temperature variation (-80 degrees to 25 degrees C). A high sensitivity has been obtained by converting the cell into a 3-m-long, high-Q cavity. This type of cell appears to particularly recommend itself for use in intensity measurements, broadband spectroscopy, analytical studies, and high frequency range work.
authors.affiliation: Groupe de Spectroscopie et des Techniques Microondes, E.R.A. no. 22-Interactions Moléculaires, Université de Nancy I, Nancy Cedex, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Thiebaut
authors.forename: G
authors.initials: G
authors.lastname: Roussy