Automatic Pockels Linearization

Some time ago, we described a procedure to manually create a look up table for the laser power slider to achieve linear power.  Now, if you have a Thorlabs’ PM100D meter your job has been made much easier, as Scanbox can perform the calibration automatically. As a first step, you will need download and install the…

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Blanking the laser between trials

Sometimes, during long behavioral sessions, it is advantageous to turn off the laser between trials to minimize damage while keeping the microscope scanning.  To do this without introducing any additional noise that may influence the behavioral state we use the Pockels cell.  Scanbox now allows one to blank the laser by sending a command over…

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Linear power

The following procedure will allow you to define a linearization table for your Pockels’ cell so you can obtain a linear power change with equal steps in the value of the power slider in Scanbox. During imaging the laser power is controlled by an 8-bit DAC that ranges from from 0V (at a DAC register value…

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Simultaneous control of an electrically tunable lens and a pockels cell

We are preparing Scanbox for fast, volumetric scanning, by providing simultaneous control of an electrically tunable lens (to focus on different planes) and a Pockels cell (to control laser power). The Scanbox card has an integrated, 12-bit current source used to control the focus tunable lens. Similarly, an integrated DAC on the Scanbox card controls laser power via a Pockels cell. The…

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Pockels cell modulation via look-up tables

The Scanbox card keeps the laser power per pixel constant across the imaging field despite variations in dwell time during the resonant scanning cycle.  It also blanks the laser entirely near the edges of each line.  The shape of the modulation signal is fully programmable, although each change requires a firmware update to the board. We achieve…

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