Longitudinal Dispersion Compensation for the Very Large Telescope Interferometer
Abstract
The Very Large Telescope Interferometer [1,13] will be operated in air which will introduce small optical path fluctuations due to internal turbulence [4,6] and dispersion effects. Both may contribute to fringe contrast decrease. Longitudinal dispersion effects can be corrected by inserting an appropriate glass of variable thickness in one arm of the interferometer [3,5,11,12]. This paper presents a new method applied to VLTI in order to select the optimum glass, according to both the observing wavelength and the spectral bandpath, and to calculate its thickness. Results are presented in terms of improvement on the fringe contrast.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- September 1996
- DOI:
- 10.1007/BF00645784
- Bibcode:
- 1996Ap&SS.239..305L