THORLABS OTKB/M User Manual page 12

Modular Optical Tweezers
Step 4: Vertical Segment (OTKB-3)
Remove any caps at the end of the segment, which are used to protect the optics during shipment.
Carefully connect the vertical segment to the beam expander segment. If the cage rods from the beam expander
do not easily fit into the holders on the vertical segment, it might be necessary to loosen the three mounting screws
which clamp the vertical segment onto the large vertical post (Thorlabs item number DP14A). Make sure the cage
rods connecting the beam expander segment and the vertical segment slide in all the way before using the clamping
screws on the cage rod receptacles (Thorlabs item number ERSCA). Based on the position of the cage rod
receptacles it might not be possible to reach all clamping screws. Make sure to tighten at least two clamping screws.
Use the large clamps included with the vertical segment to fix the assembly in place (Thorlabs item number CL5).
Mirror 3
Figure 7 Left Side: Vertical segment with final Iris locations, Right Side: Upper dichroic and visible light
Next remove the upper dichroic mirror holder using a 1/16" (1.3 mm) hex key to remove the four screws holding the
inner ring of the dichroic base plate and temporarily replace the illumination light source with an iris. Place iris 1
with the cage plate used in step 3 back to its final position. Use iris 2 at the light source position. Use a two point
alignment to align the beam along the vertical path, i.e. only adjusters on mirror 2 and on mirror 3 should be used.
It may help to use cage rods to mount the IR viewer during alignment.
Afterwards mount Iris 1 at its final position and put the illumination light source back. Re-mount the dichroic, making
sure it maintains a 45° angle with the respect to the light path.
Page 10
Illumination
Source
Iris 2
Iris 1
Cage Rod
Receptacle
source removed, iris temporarily mounted on top.
Mirror 2
Chapter 5: System Setup
Light Source
Removed; Iris
Used During
Alignment
Dichroic
Holder
19590-D02