| Description |
154 pages. |
| Summary |
"Specific performance characteristics of a krypton laser were measured. Evaluation criteria were dictated by the proposed use of the laser as a multi-wavelength illumination source. The laser output power, spectral power distribution, and output stability were measured as a function of wavelength and transverse mode order, to determine optimal operation characteristics. Data are presented defining the compromise between laser output power and beam divergence when the laser is operated multi-wavelength, and in several low-order transverse modes. There is an advantage of increased output power when the laser is operated in transverse modes higher in order than TEM₀₀, but beam divergence also increases with mode number and wavelength. In addition, significant output instability occurs, caused by competition effects among the simultaneously oscillating longitudinal modes and among the multi-wavelength, low-order transverse modes. The instabilities are increased by competition among the several transitions, caused by shared krypton ion energy levels. The magnitude and frequency of the resulting laser intensity fluctuations were measured and data are given relating output instability to wavelength and transverse mode order. In addition to the near-random intensity fluctuations caused by competition effects, the laser output can be modulated at discrete frequencies by strong plasma instabilities. The frequency and magnitude of the discrete frequency modulations were measured, and the results are presented as a function of discharge current"--Abstract, leaves ii-iii. |
|
