Basic calibrating procedures

In order to produce good images you will need to ensure that the following are true. The order in which the following constraints are listed is the order in which you should perform the alignments.

• The X and Y scanners must displace the beam along orthogonal directions and the beam must leave the scanhead at 90 degrees to the angle with which it entered. This alignment may need to be done with the scanhead removed and sitting on an optical table.
• The X and Y stages must displace the sample along orthogonal axes.
• The X scanner should move the beam along the direction of motion of the X stage and the Y scanner along the direction of motion of the Y stage. Rotating the stage assembly about its centre should acheive this.
• The scanning plane (imaging plane) should be parallel with the plane of motion of the X and Y stages. You will need to mount the stages on three points of contact with at least two being height adjustable.
• The blade must be parallel to the Y stage such that the surface of the sample remains the same distance from the objective as it is translated in Y. Adjust the blade angle to achieve this.
• You should calibrate the number of microns per pixel.