Head, Probe and Sample Preparation
Laser Alignment
78
MultiMode SPM Instruction Manual
Rev. B
5.2
Laser Alignment
This section describes two methods for aligning the laser for all modes except STM. The
fi
rst
method uses an Optical Viewing Microscope (OMV). The second method is a “projection” method.
In the projection method you remove the MultiMode head and shine a laser onto a piece of white
paper, producing diffraction patterns. The interpretation of these patterns serves as a guide to
aligning the laser. The projection method is more often used if you do not have an OMV, or if your
sample does not re
fl
ect the laser well enough to be viewed in the OMV.
5.2.1 Method 1: OMV Method
1. Use the OMV to locate and focus on the cantilever. Then focus below the tip on the surface.
Next bring the head/tip down using the front manual screws and the stepper motor until the
cantilever is almost in focus.
Note:
If you have an EV or JV scanner, you can just adjust the stepper motor in this
step.
2. While remaining in focus, use the OMV stage screws to locate the red laser reflection spot.
Once located, use the manual laser knobs on top of the head to move the laser onto the end of
the cantilever.
3. Place a piece of paper in front of the photodetector to ensure the laser reflection is solid,
Insert a narrow (1cm wide) slip of paper into the head and observe the laser reflected from
the top side of the cantilever. This is a very quick method for checking laser alignment.
Note:
Because the slip of paper prevents light from reaching the photodetector, the
sum signal cannot be monitored while using this method.
WARNING:
Staring at a bright beam or reflection can result in eye damage. Be
sure that you are using a magnifier with a laser filter installed.
AVERTISSEMENT:
Fixer un faisceau lumineux puissant ou sa réflexion peuvent
entrainer des dommages au niveau des yeux. Il est impératif
d’utiliser un filtre laser
.
WARNUNG:
Der direkte Blick in den Laserstrahl oder dessen Reflektion kann
Augenschädigungen hervorrufen. Bitte stellen Sie auf jeden Fall
sicher, daß ein optisches Gerät, mit dem Sie in den Laserstrahl
schauen, mit einem Laserschutzfilter ausgestattet ist.
