Optical Trap Kit
19590-D04-V15; Apr 12, 2012
Page 17
www.thorlabs.com
6.3 Vertical segment
1.
Attach a C1500 clamp to an LCP01 (ensure that the C1500 face is parallel to the LCP01 before
locking) and slide-hold to the Dynamically Damped 14” post, DP14.
2.
Stack the LCP01 on top of the LCP02 and connect them using four ER1 cage rods as in Figure
6.3.1 (you may remove the threaded studs from both ends of the cage rods).
3.
Adjust the height of the C1500 until the four ER1.5 rods can slide into the four cage rod holes on
the C6W, just enough such that you can lock them using the setscrews on the sides of the C6W,
while not interfering with the rotation of the B4C in the cube.
4.
Lock the C1500 to the DP14.
5.
The DP14 Post can now be locked down to the table (using CL5 clamps) along with the CPB1
bases (using CL6 clamps) when the holes in the bases do not align.
6.
Attach an SM1D12D to the LCP02.
7.
Temporarily attach four ER12 cage rods to the
ends of the four ER1 cage rods used to hold the
LCP01 and LCP02 plates together.
8.
On the other end of the ER12 cage rods attach an
LCP02.
9.
Attach an additional SM1D12 iris to the upper
LCP02 as shown in Figure 6.3.1.
10.
Use this arrangement to align the beam to the
center of the vertical cage segment. Make sure
you use protective glasses when doing this. The
B4C is used to align the beam through the lower
diaphragm while the KCB1 is used to align the
beam through the upper diaphragm. Neither
should require much adjustment. First the lower
iris is wide open. Then you gradually close this
and if necessary, use the kinematic adjusters to
ensure the beam goes through the center. In most
cases, just small adjustments on the adjusters on
the B4C will center the beam. When the lower
iris has its smallest aperture, you should still see
the beam going through after your adjustments.
Make sure the beam through the iris is optimal.
Then fully open this iris and align the beam through the upper iris. Start when the upper iris is
fully open, and gradually decrease the aperture while adjusting the beam position with the knobs
on the KCB1 until you have the most transmission through smallest aperture size of the upper
diaphragm. Now close the lower diaphragm also and ensure that you have optimal transmission
through both irises, when they are at the smallest apertures. It may be necessary to iterate this
alignment before you achieve the maximum transmission through both smallest apertures.
**Centering of the beam along this path is very critical. A Thorlabs power meter (not included) with an SM1 threaded
measurement head (e.g., PM100D with S121C) will allow you to verify the alignment by maximizing the transmitted power
when both apertures are nearly closed. As a guideline, using the 350mW laser
,
at a drive current of 100 mA and the
diaphragms 8˝ apart, both SM1D12D closed, the measured power should be around 0.7 mW.**
Figure 6.3.1: The vertical segment during alignment.
C1500
LCP01
ER1
DP14
