CPC G02B 13/14 (2013.01) [G02B 13/02 (2013.01); H01L 27/14627 (2013.01); H01L 27/14649 (2013.01)] | 20 Claims |
1. An athermalized Short-Wave InfraRed (SWIR) telephoto lens device for a tracking camera comprising, in order, from a remote object to an image plane:
an Aperture Stop (AS);
a first optical element having a first element first surface radius of 23.16 to 23.24 mm convex, and a first element second surface radius of 46.21 to 46.29 mm concave;
a second optical element having a second element first surface radius of 22.68 to 22.76 mm convex, and a second element second surface radius of 46.21 to 46.29 mm concave; and
a third optical element having a third element first surface radius of −56.81 to −56.89 mm concave, and a third element second surface radius of 16.61 to 16.69 mm concave; and
a housing to hold at least said first, second, and third optical elements comprising a material having a Coefficient of Thermal Expansion (CTE) of about 8.8 ppm/K at room temperature;
whereby an image is formed.
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