FlexAFM laser and detector alignment

Part 1: Laser-Cantilever Alignment

Step 0

The following laser-cantilever alignment steps assume that the laser is not touching any part of the cantilever or chip.

To increase the size of the laser spot, hold the AFM scan head 10-20 cm above your workbench while you follow these steps.

position-alignment
laser_off_cantilever

Appearance of laser spot when not on cantilever

Step 1 - Find the edge of the chip

Insert the laser alignment tool (LAT) into the 4th hole and turn until the laser is blocked by the edge of the chip. Finally, move the laser so that it just re-appears past the edge of the chip.

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find_chip

Step 2 - Find the cantilever

Insert the LAT into the 3rd hole and turn until the laser passes over the cantilever. You should see the laser spot get blocked and then reappear on the other side. Finally, move the laser back onto the cantilever so that the laser spot is blocked.

turn3
find_cantilever

Step 3 - Move to end of cantilever

Insert the LAT back into the 4th hole and turn until the laser reaches the end of the cantilever and the laser spot gets bright again. Finally, move the laser back onto the end of the cantilever.

turn4
end_cantilever

Step 4

Check the Deflection Signal Intensity in the Laser Alignment Dialog. The mark should be within the green bar. Using the LAT go between the 3rd and 4th holes and try to maximize the Detector Signal Intensity.

laseralign0

Maximized Detector Signal Intensity

end_cantilever

Final Position of Laser

Part 2: Detector Alignment

Step 0

After the laser is aligned to the cantilever, the next step is to align the detector to laser spot that is reflected from the cantilever. The goal is the get the laser spot, denoted by the green dot, into the center of the square. The next two steps can be done in any order.

laseralign0

Initial Position

laseralign2

Goal

Step 1

Insert the LAT into the 1st hole and turn until you have centered the Lateral Deflection Signal.

turn1
laseralign0

Before

laseralign1

After

Step 2

Insert the LAT into the 2nd hole and turn until you have centered the Normal Deflection Signal.

turn2
laseralign1

Before

laseralign2

After

Step 3

Go between Steps 1 and 2 to fine tune the position of the detector until you are satisfied.