A specialized containment cell with optically transparent apertures, in conjunction with a laser interferometer system provides the means for non-contact displacement measurements of electro-active (piezoelectric and electrostrictive) materials to be performed under controlled conditions of pressure, temperature and applied voltage. A sample of electro-active material is placed inside the cell. Electrical connections are made from a high voltage power source to the sample through the cell. Thermoelectric heaters/coolers and a cooling water heat sink built into the cell control the temperature of the sample. The cell is flooded with a dielectric oil pressurizing the interior of the cell to a desired pressure. The cell is optically aligned to the interferometer, and with the cell heated to the proper temperature, a voltage is applied to the sample as the interferometer measures the displacement of the sample.