CM March14

We redesigned the confocal optical setup:

• The beam expander was integrated into the relay lenses. Now the setup has fewer parts to adjust.
• We will use an achromatic lens pair for the relay lenses.
• We have switched to 1 inch optics* instead of 2 inch optics
• The dichroic for the bright field image was moved in front of the relay lenses, after the objective (in the bright field beam path). The bright field image is not shrunk by the beam expander and we can be more confident in the appropriateness of 1 inch optics.
• The PMT is horizontal instead of vertical for greater stability
• The pinhole screws onto the z-direction adjuster so pinhole sizes can be swapped without difficulty
• Spacial placement of beam path is such that a second laser and a photodiode (for laser intensity measurements) can be added easily in the future and such that the amount of beam expansion is easily changed.