Head, Probe and Sample Preparation
Laser Alignment
Rev. B
MultiMode SPM Instruction Manual
79
Figure 5.2a
Laser Alignment with Piece of Paper
4. Reposition the laser with the screws on top of the optical head, if necessary.
5.2.2 Method 2: The Projection Method
You can also align the laser by moving the laser beam relative to the cantilever while observing the
laser spot on a piece of white paper below the optical head. If the laser is not on the cantilever
substrate, the laser appears as a bright red spot on the surface below. When the laser is aligned on
the cantilever, a shadow appears on the surface below.
The X direction runs along the major axis of the substrate (parallel to the length of the cantilever).
The right-front laser control knob, atop the optical head, controls the laser beam movement along
the X direction. The back-left laser knob, atop the optical, head, moves the beam along the Y
direction perpendicular to the cantilever and substrate's major axis. In the vision system display, the
X direction is right-to-left across the screen, and the Y direction is top-to-bottom.
The procedure for aligning the laser is slightly different between TappingMode and Contact Mode
AFM. The sections below detail the procedures for aligning the laser on the cantilever and tips for
each mode respectively.
CAUTION:
Turn down the illuminator intensity before proceeding with laser
alignment.
