Final PIL optical configuration
At the outset, the development of the PIL optical design was never considered to be trivial; however, the design team found the task of developing an optical system for the PIL to be quite a challenge. The combination of image deformation, wavefront error, distortion, and other requirements called for a unique optical solution.
Convex cylindrical surface
10 arcsec radial
> 75% Strehl
> 1500 and < 2000 pixels
> 25 mm
35 +0.0,-0.01 mm
Table 2: PIL optical system performance analysis summary
The pupil imaging lens assembly has been developed to meet a challenging set of requirements. On one hand, there is the design of a mechanism that can rotate payloads to a fine repeatability within a cryogenic environment. Then there is the design of one set of lenses that, once inserted, can drastically alter the prescription of a telescope. Furthermore, the optical system must have exceptional performance over a wide range of parameters. The design team has successfully shown that the PIL precision mechanism and optical design support this demanding set of requirements.
PIL three lens optical system.
The three lens system (Figure 11) with two wedged spherical lenses and one plane cylinder lens was developed through an iterative process, and in the end, the system was analyzed to meet the stringent requirements (Table 2).
Three lens optical performance