The Omega2000 optics are four lenses of different materials, acting as a corrector and changing the F-number of the primary slightly to the final F/2.35 which are needed to archive the 0.45" / pixel. The optics are achromatic from 0.85 µm to 2.4 µm without refocusing. Distortion is 0.06 % which is less than one pixel from center to corner. All graphs for the optics as built.
Transmission (ASCII table)
Spots - polychromatic i.e. 0.85 - 2.4 µm
Spots - Z band / Spots J band / Spots H band / Spots K band
Encircled Energy - polychromatic,
diff. limit calculated for 0.85 µm
In addition, there is a warm mirror
baffle system outside the dewar to reduce the background seen by the
detector. The mirrors are rings with ellipsoidal shape directing all rays
coming from inside the dewar back to
the dewar (back to cold environment). For observing in K band, there
is a moveable baffle which vignettes the beam to a certain amount, maximizing
the S/N ratio.
Contact Peter Bizenberger for more information.