Liquid Crystal Controller
18828-D02 Rev F, Sept 23, 2011 Page
5
www.thorlabs.com
Part 2. Product Overview
The LCC25 is a liquid crystal controller compatible with all Thorlabs LC Variable
Retarders. The LCC25 will drive most nematic liquid crystal devices. The liquid crystal
device is connected to the BNC voltage output port. The amplitude of the output voltage,
adjusted by the front panel knob, and external signal, and a computer via a USB interface,
controls the retardance of the LC device.
The LCC25 produces a 2 kHz AC square wave with an amplitude that is adjustable from
0 to 25 V
RMS
.
The unit features two selectable set points, Voltage 1 and Voltage 2. Both set points are
controlled by the user, and they produce a square wave that is plus/minus the set point.
For example, if the user sets Voltage 1 to 15.000, the output would be a ±15.000V, 2 kHz
square wave (see figure 1).
Figure 1: A 2 kHz Square Wave Output with no Additional Modulation
The user can also select a modulated output with a frequency range of 0.5 to 150 Hz. The
First cycle will be equal to Voltage 1 and the second cycle will be equal to Voltage 2 (see
figure 2)
