ScanImage 2018 : Calibration of the resonant scanner's amplitude at different zoom levels

The amplitude of a resonant scanner does not always change linearly with the control voltage. Since the galvanometric mirror for the scan in y-direction has a linear response, this can lead to an image distorton in x-direction at different zoom levels.

ScanImage has a built in tool to correct for the non-linear amplitude of the resonant scanner. To access this feature, execute the following command in the Matlab command prompt:

>> hSI.hScan2D.plotFov2VoltageCurve();

This will show the Resonant FOV to Voltage Calibration Curve, which allows you to manipulate the zoom-to-voltage lookup table for the resonant mirror. After enabling the feature with the checkbox in the lower left corner, start a focus and adjust the zoom level until the distortion becomes visible. In the calibration window, add a control point and adjust the control point's position using the arrow buttons until the distortion is removed. Repeat the process for multiple zoom levels.

hSI.hScan2D.useNonlinearResonantFov2VoltsCurve = true; % this will bring up the calibration window
hSI.hScan2D.createResFov2VoltsCalControlPoint();
hSI.hScan2D.adjustResVoltageCal(0.1); % increase the voltage of the current point by 0.1%; use negative values to decrease the voltage
 
% additional commands
hSI.hScan2D.removeResFov2VoltsCalControlPoint(); % remove a calibration point at the current zoom level
hSI.hScan2D.plotFov2VoltageCurve(); % show the calibration curve again after the window was closed
hSI.hScan2D.clearResFov2VoltsCal(); % reset the calibration curve