Table 1. Sensitivity analysis for misplacement of lenses along the optical axis.
| Design separation (mm) |
Uncompensated
full-range (mm) |
Compensated positive half-range (mm) | Compensating tube lens shift (mm) | |
|---|---|---|---|---|
| d1 | 200 | 123 | 2200 | −2.9 |
| d2 | 2.5 | 0.1 | 1.4 | -3.5 |
| d3 | 530 | 1615 | 4000 | −0.32 |
| d4 | 32 | 6 | 1.9 | −0.03 |
| d5 | 80.5 | 0.1 | 2 | -4.9 |
| d6 | 5 | 0.1 | 1.2 | -3.5 |
| d7 | 16.1 | 1.6 | 4.1 | −0.65 |
| d8 | 5 | 0.1 | 1.5 | -4.32 |
| d9 | 80.5 | 0.1 | 1.9 | -4.68 |
| d10 | 31 | 3.4 | 1.2 | −0.04 |
| d11 | 143.9 | 2.5 | 1.1 | −0.1 |
| d12 | 1 | 0.8 | 3.7 | -1 |
| d13 | 387.2 | 0.2 | –* | –* |
| d14 | 1 | 2.9 | 6.2 | −0.45 |
| d15 | 114.5 | 6.7 | –* | –* |
| d16 | 28 | 0.1 | 2.2 | −6.3 |
| d17 | 102 | 110 | 32 | −0.01 |
The listed separations are defined as: d1 ≡ last table telescope to edge diverging pair, d2 ≡ edge diverging pair spacing, d3 ≡ edge diverging pair to X-scan mirror, d4 ≡ X-scan mirror to first f-θ scan lens, d5 ≡ first f-θ scan lens to first compensating pair, d6 ≡ first compensating pair spacing, d7 ≡ first compensating pair to second compensating pair, d8 ≡ second compensating pair spacing, d9 ≡ second compensating pair to second f-θ scan lens, d10 ≡ second f-θ scan lens to y-scan mirror, d11 ≡ Y-scan mirror to compound scan lens, d12 ≡ compound scan lens spacing, d13 ≡compound scan lens to compound tube lens, d14 ≡ compound tube lens spacing, d15 ≡ compound tube lens to third compensating pair, d16 ≡ third compensating pair spacing, d17 ≡ third compensating pair to objective back aperture plane. The design separation predicts a peak in the normalized intensity of the Huygens' point spread function of 90% or greater across the full X- and Y-deflection range. The uncompensated range indicates the full range over which misplacement of each single element maintains > 80% predicted point spread function. The compensated range indicates the positive half range over which > 80% predicted point spread function can be recovered by adjustment of the compound tube lens position by the corresponding displacement listed in the last column. (*) d13 and d15 represent misalignment of the compound tube lens relative to a neighboring element; therefore compensation by displacement of the compound tube lens is inappropriate for these measures. In the case of d13, a 5-mm misplacement of the compound tube lens could be compensated by a −2.37 mm shift in the spacing of the edge diverging pair.