NIIS Optical Design
Lens Specifics
The optical design for NIIS was developed by Charles Harmer (NOAO)
and is derived from his design of FLAMINGOS. It features a two-element
corrector which produces a flat and well corrected primary focal plane.
It features a collimator/camera design to allow for a collimated beam
for filters and grisms. The collimator consists of a Cooke Triplet and
and a field lens which images the telescope pupil near the filters
enabling a cold pupil stop. The camera follows the filter wheel and
produces excellent images over the full extent of the Hawaii-2 array.
All radii and center thickness values are specified in millimeters
(mm). CC indicates concave surfaces and CX indicates convex surfaces.
Positive values indicate a radius of curvature on the sky side of the
lens while negative values indicate that the radius of curvature is
found between the lens and the detector. Tolerance data are given for
each diameter, radius, and thickness. The edges of each lens have
diamond-turned chamfers at 45 degrees to mate with corresponding
surfaces on the lens mounts.
The optics were manufactured, diamond-turned, and tested by Optical
Solutions Incorporated (http://www.opticalsolutionsinc.com). They also
mounted each lens in its cryogenic lens mount using a precision
air-bearing table. Each lens was then mounted into one of the three
lens stacks at the University of Wyoming.
Two Element Corrector
| Lens ID | Material | Diameter | Radius #1 | Radius #2 | Thickness |
|---|---|---|---|---|---|
| Corr. #1 | CaF2 | 204.0+-0.1 | 703.1+-1.0 CX | 531.0+-1.0 CC | 20.0+-0.1 |
| Corr. #2 | CaF2 | 201.56+-0.1 | -165.1+-0.3 CC | -186.2+-0.4 CX | 30.0+-0.1 |
Four Element Collimator
| Lens ID | Material | Diameter | Radius #1 | Radius #2 | Thickness |
|---|---|---|---|---|---|
| Coll. #1 | CaF2 | 202.0+-0.1 | -1112.7+-4.0 CC | -266.5.0+-0.4 CX | 47.5+-0.1 |
| Coll. #2 | BaF2 | 160+-0.1 | 790.9+-1.5 CX | -286.1+-0.5 CX | 44.4+-0.1 |
| Coll. #3 | CaF2 | 136+-0.1 | -367.2+-0.7 CC | 250.9+-0.5 CC | 15.7+-0.1 |
| Coll. #4 | BaF2 | 130+-0.1 | 293.9+-0.3 CX | -19724+-20 CX | 20.0+-0.1 |
Eight Element Camera
| Lens ID | Material | Diameter | Radius #1 | Radius #2 | Thickness |
|---|---|---|---|---|---|
| Cam. #1 | ZnSe | 114.0+-0.1 | 123.2+-0.1 CX | 97.00+-0.05 CC | 18.6+-0.1 |
| Cam. #2 | BaF2 | 121.0+-0.1 | 129.16+-0.06 CX | 193.6+-0.2 CC | 12.7+-0.1 |
| Cam. #3 | BaF2 | 159.0+-0.1 | 260.2+-0.3 CX | -283.7+-0.1 CX | 40.0+-0.1 |
| Cam. #4 | IR Silica | 136.0+-0.1 | 411.2+-0.4 CX | 166.94+-0.07 CC | 10.0+_0.1 |
| Cam. #5 | BaF2 | 130.0+_0.1 | -1740+_6.0 CC | -122.4+-0.1 CX | 40.0+-0.1 |
| Cam. #6 | ZnSe | 101.0+-0.1 | -58.47+-0.06 CC | -75.98+-0.08 CX | 18.8+-0.1 |
| Cam. #7 | BaF2 | 74.0+-0.1 | -88.22+-0.08 CC | -99.6+-0.1 CX | 26.1+-0.1 |
| Cam. #8 | ZnSe | 59.0+-0.1 | 131.5+-0.1 CX | 93.44+-0.09 CC | 8.0+-0.1 |