This article describes how to set up a phaseshifter for interferometers with OptSuite using a custom piezo-tranducer control device.

Phase shifting is done via the USB-Port. An I/O controller (IO-Warrior 40, Code Mercenaries) is used to control a piezo transducer (P-239.00, Physik Instrumente). The IO-Warrior drives a D/A converter (MX7248, Maxim) to transform the USB digital output to the desired analog output for a high-voltage amplifier connected to the piezo transducer.

The Maxim DAC has 12 bit resolution and an outputrange from 0-5V. The piezo transducer has a maximum translation of 6μm for a input voltage from 0-1000V. This makes a step width for the phaseshifter of about 0.7nm.

A platine layout was designed especially for this purpose. It assembles the IOW the DAC and its power-suply onto one platine. Users will have to expose and etch the platine themselves as we only provide the eagle files here.

The file iow2dac.tar.gz contains the the eagle files for schematic and board as well as the libraries for the print connectors.

The following parts have to be soldered on the platine to finish it:

• USB-PrintConnector: Found in every electronics store:
• PrintConnector for power supply: A 12 V power-supply is used. The connector used if for a coaxial plug.
• BNC-PrintConnector: For the output to the amplifyer
• Resistors: 2 x 7K
• Capacitors: 1 x 10μF, 2 x 100nF
• Electrolyte capacitors: 1 x 200μF, 1 x 10μF, 1 x 0.1μF
• Resonator: A 6 MHz ceramic resonatro is needed for the IOW. Search http://www.segor.de/ for the resonator.

Your other choice is to buy the IO-Warrior 40 Starter Kit that itself ships with a platine. Now you have to take care yourself of connecting the io-ports to the D/A converter, manage the power-supply for the DAC and direct the DAC output to the amplifier. If you choose to do so, here is the pin assignment for the DAC and the IOW-ports: