The entrance "slit" is defined by the optical fiber diameter (200 microns) unless an optional slit mask is used. A 100mm focal length achromatic doublet lens collimates the light on its way to a plane reflectance grating. The camera is a 136mm f/2 commercial SLR lens. Because the design of this lens is proprietary, the lens must be approximated by a paraxial surface. The detector is a 2048x2048 SITe CCD with 24 micron pixels. The system layout is shown here.

Spot diagrams are available: 470 nm, 570 nm, 670 nm.

A ZEMAX file is also available.

System/Prescription Data

Title: FMO Bench Spectrograph
Date : WED AUG 27 2003

LENS NOTES:

       	We actually use the Rolyn 20.1373 achromatic doublet, but the 
       	detailed optical info is not available. In this layout, we are 
	substituting 22.0373, which is very similar. We are forced to use
        a paraxial surface for the camera since the Nikon design is 
	proprietary.

GENERAL LENS DATA:

Surfaces                :                8
Stop                    :                1
System Aperture         : Object Cone Angle = 5.711
Glass Catalogs          : SCHOTT
Ray Aiming              : Off
Apodization             : Uniform, factor =   0.00000E+000
Effective Focal Length  :        -245.144 (in air at system temperature and pressure)
Effective Focal Length  :        -245.144 (in image space)
Back Focal Length       :        715.3667
Total Track             :        594.9422
Image Space F/#         :        3.609046
Paraxial Working F/#    :        1.929082
Working F/#             :        2.334853
Image Space NA          :          0.2509
Object Space NA         :      0.09951078
Stop Radius             :       -33.96244
Paraxial Image Height   :        2.528513
Paraxial Magnification  :       -0.385844
Entrance Pupil Diameter :        67.92487
Entrance Pupil Position :               0
Exit Pupil Diameter     :         17.0793
Exit Pupil Position     :        -32.9355
Field Type              : Object height in Millimeters
Maximum Field           :          6.5532
Primary Wave            :            0.57
Lens Units              :   Millimeters
Angular Magnification   :         3.97703

Fields          : 5
Field Type: Object height in Millimeters
#        X-Value        Y-Value         Weight
 1       0.000000       0.000000       1.000000
 2       1.638300       0.000000       1.000000
 3       3.276600       0.000000       1.000000
 4       4.914900       0.000000       1.000000
 5       6.553200       0.000000       1.000000

Wavelengths     : 3
Units: Microns
#          Value         Weight
 1       0.470000       1.000000
 2       0.570000       1.000000
 3       0.670000       1.000000

SURFACE DATA SUMMARY:

Surf     Type    Comment      Radius   Thickness     Glass  Diameter  Conic
 OBJ STANDARD               Infinity       339.6             13.1064      0
 STO STANDARD    22.0373    471.4757           3       SF5       100      0
   2 STANDARD               160.8234          17       BK7       100      0
   3 STANDARD              -213.9037    574.9422                 100      0
   4 COORDBRK                      -           0                   -      -
   5 DGRATING               Infinity           0    MIRROR  91.74693      0
   6 COORDBRK                      -        -100                   -      -
   7 PARAXIAL                      -        -135            102.3902      -
 IMA STANDARD               Infinity                        50.04841      0