March 12, 2022
...
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)
...
| Description | Qty | Part # | Details | Purchase Date |
|---|---|---|---|---|
| Ø2" UVFS Wedged Window, Uncoated | 8 | WW42012 | 8/8. | 01/30/24 |
| 60 mm Cage Cube | 8 | LC6WR | 8/8. | 01/30/24 |
| Light-Tight Blank Cover Plate for 60 mm Cage Cube, 1/4"-20 Tap | 10 | LB1C | 10/10. | 01/30/24 |
| SM2-Threaded Cover Plate for 60 mm Cage Cube | 4 | LB2C | 4/4. | 01/30/24 |
| Kinematic Prism Platform for 60 mm Cage Cube, Imperial Taps | 6 | LB4C | 6/6. | 01/30/24 |
| 60-mm-Cage-Compatible Rectangular Filter Mount | 2 | LFFM1 | 2/2. | 01/30/24 |
| Ø2" Optic Mount for 60 mm Cage Cube with Setscrew Optic Retention | 8 | LB5C1 | 8/8. | 01/30/24 |
| 60 mm Kinematic Cage Cube Connector | 8 | DFM2-CC | 8/8. | 01/30/24order blocking filter, controller servo |
| 6mm cage connector rods of various lengths | all received. | |||
| fast plano-convex lenses | various | all received. | ||
| optical shutter? Thorlabs | ||||
| optical chopper following monochromator | ||||
| condensing lens for photodiode | ||||
| order blocking filter, controller servo |
We note the reflective designs in this paper which document a 4-element system that adequately* preserves the initial polarization / phase of light.
Status updates:
An initial version of the RACBP was constructed in the benchtop lab setup on Feb. 22.
Initial testing with a 532nm laser unfortunately showed strong and tightly spatially located double-bounce propagation through the system, indicating that the 30-arcmin wedge on the wedge windows purchase would be insufficient for canceling double-bounce issues.
Consequently, plano-convex lenses of the fastest f-ratio were ordered and installed the following week as replacements to the wedge windows; initial observation reveal that this modification
appears to successfully cancel out double bounces, representing a step closer to taking controlled flux measurements through the system at this proof-of-concept stage.
In-progress/next steps: finalizing modelling results for system ; angular alignment tolerance, verification of polarization effects.
Reworking physical layout and installing double monochromator system and operation with expanded beam profile.
Kane To-Do:
polarization state output as fxn of angle of incidence for BK-7 and Fused Silica ... quantitative calcns
...