Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637765
Title: Spectroscopic investigation of metal vapour lasers
Author: Karyono
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1991
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Abstract:
The study is concerned with the characterization of a HCD HeCd+ laser design and its spectroscopic investigation. The design, construction and operation of the laser are described, and in particular the advantages of the hollow cathode discharge for achieving the population inversion of the laser transitions are discussed. Simultaneous C.W. oscillation on seven transitions of the HeCd+ laser tube has been achieved, i.e. at 441.6 nm (blue), 533.7 nm and 537.8 nm (green), 635.5 nm and 636.0 nm (red), 723.7 nm and 728.4 nm (infra red). The simultaneous operation of blue, green and red lines generates 'white light'. Thus this laser has potential applications in a variety fields like e.g. in colour scanning, colour printing, holografic film recording and storage, and monitoring of compound semiconductor growth. A spectroscopic study of a pure helium discharge has been conducted and the major results for pressure and discharge current dependence are discussed to establish missing links in the understanding population mechanisms for the upper level of the different transitions in the HeCd+ laser. The green laser transitions had generally been assumed to be generated via radiative cascade through the red laser lines. However, the existence of the green laser lines at high pressures gave an argument that the population inversion of the green upper levels is produced by collisional processes between the Cd atoms and molecular helium ions, He2+. The observation of a number of He2* bands, at the expense of atomic lines, confirms the important role of molecular helium. The most striking feature in this study was the observation of the banded emission extending up to 40 nm around the laser lines; the observed bands have to be ascribed to emission from the (He..Cd)+. Finally, preliminary experiments based on the exploitation of the optogalvanic effect were carried out in order to measure gain and losses of the transitions in the HeCd+ and the molecular emission of (He..Cd)+.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.637765  DOI: Not available
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