Optical position sensor for the BWS Upgrade PSB

Optical position sensor for the BWS Upgrade: PSB BWS External Focuser and Viewport Tests Jose Luis Sirvent Blasco Ph. D. Student BWS Upgrade Electro-Mechanical design Meeting 19/11/2015 BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 2

0. Test Procedure • Optical system with different configurations tested • All measurements with same disk rotaional speed and laser optical power. • With and without viewport on the optical path. • Glass disk 3 rd track (20 um) • Quick check for spot size determination BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 3

1. External Focuser and Viewport: 1. 1 Current Configuration: SPS Lenses Without Viewport 14 um Track 18. 16 mm Spot size approx = 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 4

1. External Focuser and Viewport: 1. 1 Current Configuration: SPS Lenses With Viewport 14 um Track 18. 92 mm Spot size approx = 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 5

1. External Focuser and Viewport: 1. 2 New lenses in SM 05 M 1 Lens tube without viewport 14 um Track 41. 2 mm BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 6

1. External Focuser and Viewport: 1. 2 New lenses in SM 05 M 1 Lens tube with Viewport 14 um Track 41. 61 mm BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 7

1. External Focuser and Viewport: 14 um Track 1. 3 New lenses in SM 05 M 2 Lens tube without Viewport Config-1 28. 9 mm Spot size approx = 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 8

1. External Focuser and Viewport: 14 um Track 1. 3 New lenses in SM 05 M 2 Lens tube with Viewport Config-1 29. 61 mm Spot size approx = 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 9

1. External Focuser and Viewport: 14 um Track 1. 4 New lenses in SM 05 M 2 Lens tube without Viewport Config-2 35. 02 mm Spot size slightly > 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 10

1. External Focuser and Viewport: 14 um Track 1. 4 New lenses in SM 05 M 2 Lens tube with Viewport Config-2 35. 47 mm Spot size slightly > 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 11

1. External Focuser and Viewport: 10 um Track 1. 4 New lenses in SM 05 M 2 Lens tube with Viewport Config-2 35. 47 mm Spot size slightly > 20 um BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 12

2. Conclusions: 2. 1 General considerations • Lenses combination usable for Disk-Focuser Distances: 35 -40 mm • Viewport effect: • • Zemax Simulations Introduces 14% optical loss. Material interface adds 0. 5 mm extra focal lengh No light dispression / reflections / aberrations Nice agreement with simulations. Real Distances D 1 = 14. 2 mm Fibre connector & Retainign Rings D 0 = 3 mm Lens & Retaining Rings D 2 = 12. 4 mm Adjustable Rage varying D 1 D 3 = up to 35 -40 mm Custom Lens tube: Internal min length for optics 30 mm Some freedom for adjustments 5 mm Required lens tube interlal length 35 mm BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 13

2. Conclusions: 2. 2 Modification required in Custom Thorlabs Lens tube : 7 mm longer +7 mm BE-BI-BL Jose Luis Sirvent Blasco (jsirvent@cern. ch) 14

BE-BI-BL Jose Luis Sirvent Blasco 15 (jsirvent@cern. ch)