March 12, 2022
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At 808 nm:
| angle (degrees) | Rp | Rs |
|---|---|---|
| 0 | 0.041365 | 0.041365 |
| 5 | 0.040948 | 0.041784 |
| 10 | 0.039693 | 0.043069 |
| 15 | 0.037593 | 0.045301 |
| 20 | 0.034640 | 0.048630 |
If angle of incidence is 10 degrees, reflected beam rotates by 20 degrees. If beam of diameter D rotates by theta, distance it must travel to not have incident and reflected overlap obeys tan(theta)=D/L so L/D=1/tan(theta)
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Bought some 6 inch aperture concave optics on eBay.
Bought Omegon 203mm aperture, 2436mm collimator. A 100 micron diameter fiber subtends an angle of 100E-6/2.436 radians = 8.5 arcsec.
Beam is f/12. Back focal length from flange is 23 cm, from focuser is 14 cm. Allowable aperture for 2 arcsec diffraction limit (so it is subdominant relative to geometrical optics)
is 10E-6=400 nm/D do D > 400e-9/10e-6 => D> 40mm so 2 inch (50mm) optics should be fine.
References
Large optical wedge vendor, example: https://www.precisionoptical.com/precision-optics/optical-flats/unmounted-reference-flat/
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