Galvanometers

Galvo mirrors are used for fast scanning, shadow reduction, and occasionally as stages (see Analog-Controlled Galvo/Piezo).

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National Instruments

Multiple types of galvanometers have been used, including Cambridge Technologies/Novanta, Thorlabs, and ScannerMAX. Each of these devices are externally controlled via analog signals delivered from an NI-based data acquisition card.

Configuration File

microscopes:
  microscope_name:
    galvo:
       -
        hardware:
          type: NI
          channel: PXI6259/ao1
          min: -1.0
          max: 1.0
        waveform: sawtooth
        phase: 0
       -
        hardware:
          type: NI
          channel: PXI6259/ao1
          min: -1.0
          max: 1.0
        waveform: square
        phase: 0

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Applied Scientific Instrumentation

In principle, this hardware type can support any analog-controlled galvanometer, including those from Cambridge Technologies/Novanta, Thorlabs, and ScannerMAX. Each of these devices are externally controlled via analog signals delivered from the ASI Tiger Controller (TG-1000).

Galvanometers can take two types of analog waveforms: sawtooth and sine. The sawtooth waveform is a periodic analog waveform. There are three duty cycle values accepted, 0, 50, and 100. If the duty cycle is 0, the waveform is a falling sawtooth waveform. If the duty cycle is 50, then it is a triangle wave. If the duty cycle is 100, the waveform is a rising sawtooth waveform. The duty cycle will be rounded to the nearest acceptable value.

The ASI Tiger Controller has a few limitations for the analog signals. The period value will be rounded to the nearest whole number of milliseconds, and for the triangle wave, the period will be rounded to the nearest even number.

Configuration File

microscopes:
  microscope_name:
    galvo:
       -
        hardware:
          type: ASI
          axis: A
          min: 0
          max: 1.0
        waveform: sine
        phase: 0
       -
        hardware:
          type: ASI
          axis: B
          min: -5.0
          max: 5.0
        waveform: sawtooth
        phase: 1.57

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Synthetic Galvo

If no galvo is present, one must configure the software to use a synthetic galvo.

Configuration File

microscopes:
  microscope_name:
    galvo:
       -
        hardware:
          type: synthetic
          channel: PXI6259/ao1
          min: -1.0
          max: 1.0
        waveform: sawtooth
        phase: 0
       -
        hardware:
          type: synthetic
          channel: PXI6259/ao1
          min: -1.0
          max: 1.0
        waveform: square
        phase: 0