Head, Probe and Sample Preparation
Laser Alignment
Rev. B
MultiMode SPM Instruction Manual
81
8. Verify the laser spot by placing a piece of paper in front of the photodetector (see
). If necessary, reposition the laser with the front-rear and back-left knobs.
Silicon Nitride Tips (Contact Mode AFM)
1. In this procedure, shining the laser beam on a piece of paper serves as a guide to aligning the
laser beam with the end of the cantilever.
2. Verify the laser beam is visible on the surface below. If it is not, turn the front-right laser
control knob counter-clockwise until the laser spot appears on the surface below.
3. Turn the front-right laser control knob clockwise to move the laser in the X positive direction
until the laser spot disappears from the surface below. Turn the right-rear laser control knob
counter-clockwise until the laser spot just reappears and stop turning the knob. The laser is
now positioned at the edge of the substrate (see Point 1 in
Figure 5.2c
Silicon Nitride Laser Alignment
4. Once the laser is positioned just off the edge of the substrate, use the back-left laser control
knob to move in the Y direction (parallel to the edge of the substrate) until the laser crosses a
maximum of four legs on the two V-shaped cantilevers (see Point 2 in
Note:
This occurs when moving in one direction (either up or down from end to end).
If the laser is close to the substrate, you should detect four distinct occurrences
of the laser spot disappearing and reappearing on the surface below.
CAUTION:
Use extreme caution if you choose to remove the optical head and
hold it over the granite or a piece of paper. Hold the head firmly,
and be mindful of the wire between the head and base. Dropping
the optical head would most likely result in damage and could
result in necessary factory repairs.
2
3
Reflections on Laser
View Screen
On cantilever leg
or tip
Near cantilever
tip
(Optimized for
Sensitivity)
1
1
