SSO 2·3m DBS Dichroics
These data were obtained by comparing the flux reaching the CCD from a
standard star with that when using no dichroic or the mirror for the
red and blue arms respectively. Thus, the effects of grating, optics and CCD
efficiency should all have been removed. One residual factor which has
not been corrected for is the polarisation of light passing through the
dichroic. The gratings' efficiency in polarised light is thought to possibly
explain the apparent low throughput in the red. This is currently under
investigation.
Please Note:
In interpretting these data, it is important to remember
They were obtained in good, but not ideally photometric conditions,
so the normalisation is arbitary.
The blue curves are not absolute, but are with respect to the mirror, which may
contain features of its own.
Single page summary of the five dichroics
Large Gif version of the above plot.
Postscript version of the above plot.
Separate plots of each individual dichroic
Notes on table:
Dichroic names are defined by the number on the cell in which they are mounted. They
do not relate to the manufacturer's naming and in at least one case are different from the
numbers given in the original hardcopy manual.
Transition gives the approximate wavelength of where transmission = reflection.
Range is the approximate wavelength range over which the transition occurs.
Blue limit is the very approximate wavelength where reflection starts to break down.
This is rather subjective, especially for dichroics 4 and 5. If you wish to observe bluewards
of this limit, you will need to use the mirror and forego any data from the red arm.
Many thanks to those who contributed to this documentation:
The Teldocs Consortium, Saskia Besier, Mike Bessell, Michelle Buxton, Paul Francis, Ken Freeman, Lisa Germany,
David Hoadley, Helen Johnston, Lisa Kewley, Joe Liske, Sean Ryan, Elaine Sadler, Raylee Stathakis, Wilfred Walsh.
Last modified: Tue Jan 25 12:48:07 EST 2000
