Accession Number:

AD0654214

Title:

ON THE PROPER USE OF LASER RADIATION IN THE CALIBRATION OF SPECTROMETER SCANNING FUNCTIONS.

Descriptive Note:

Technical rept., 1 Jan 64-1 Nov 66,

Corporate Author:

JOHNS HOPKINS UNIV BALTIMORE MD LAB OF ASTROPHYSICS AND PHYSICAL METEOROLOGY

Personal Author(s):

Report Date:

1967-06-01

Pagination or Media Count:

116.0

Abstract:

The dependence of the spectrometer scanning function on the spatial coherence of the illumination at the entrance slit implies that the spatial coherence of laser radiation must be degraded before its narrow spectral bandwidth can be used to advantage in scanning function calibration. Partial coherence theory is used to obtain conditions on the correlation function which must be obtained in order to simulate an incoherent source. It is shown that under some conditions this can be done with a source having a relatively large correlation interval provided that the correlation function has a favorable form. The experimental use of a method described by Beran and Parrent to determine the correlation function at the spectrometer entrance slit is reported. The results for an incoherent Hg source are in agreement with Hopkins concept of an effective source. Results using laser light reflected from an integrating sphere indicate that such a source may be used interchangeably with an ordinary incoherent source for scanning calibration. Author

Subject Categories:

  • Lasers and Masers
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE