ベンチトップ型電圧コントローラー、液晶デバイス用

Features

• Square-Wave Output Voltage with Adjustable Amplitude: 0 to ±25 V RMS
  • Item # LCC25: 2000 ± 5 Hz Switching Frequency
  • Item # LCC25D: 500 Hz to 10 kHz Switching Frequency
• Single Voltage and Modulated Voltage Modes
• LCC25D Controller features heating up to 50 °C for our Temperature-Controlled Half-Wave and Full-Wave Retarders
• Internally or Externally Controlled Modulation Between Two Output Voltage Amplitudes
  • Internal: 0.5 to 150 Hz
  • External (0 to 5 V TTL Signal): 0.5 to 500 Hz (Item # LCC25) or 0.1 to 150 Hz (Item # LCC25D)
• Control Using Device Front Panel or via USB Input from a PC
  • Item # LCC25D Features Additional Ethernet Connection Option
• Settings can be Saved to Allow Stand-Alone Operation via Front Panel Controls

The LCC25 and LCC25D liquid crystal controllers are compatible all of our liquid crystal (LC) devices (see Table 1.1). Both controllers produce a square-wave AC voltage output with an amplitude that can be varied from 0 V_rms to ±25 V_rms. The LCC25 controller outputs a 2000 Hz square wave while the LCC25D controller's output is adjustable from 500 Hz to 10 kHz with 1 Hz resolution. Nematic LC retarders must be driven with an AC voltage in order to prevent the separation and build up of charge, which can cause the device to burn out. Additionally, each controller automatically zeros the DC bias across the LC device to within 10 mV in order to counteract the buildup of charges.

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Figure 1.2  A plot of the output voltage of the LCC25 Liquid Crystal Controller when operated in constant voltage mode (top) and when the output voltage is being modulated between the two set voltages (bottom).

The AC output voltage amplitude for the LCC25 voltage controller can be set using the front panel controls, an external 0 - 5 VDC TTL input, or via the USB interface. When the LCC25 controller is operated in the constant voltage mode, the output of the controller will be a 2000 Hz square wave with a user-set amplitude (Figure 1.2, top). Alternatively, in Modulation mode, the amplitude of the 2000 Hz square wave output will switch between user-defined values V1 and V2 at a frequency that can be set internally (0.5 Hz to 150 Hz, see Figure 1.2, bottom) or triggered externally with 0 to 5 V TTL input (0.5 Hz to 500 Hz). The modulated mode can also be used to measure the response time of the connected LC retarder.

The AC output voltage amplitude for the LCC25D voltage and temperature controller can also be set using its front panel controls, an external 0 - 5 VDC TTL input, or via the USB or an additional ethernet interface. When operated in "V1" or "V2" mode, the output signal will be an AC square wave with a constant RMS voltage amplitude. In "Switch" mode, the output signal will be an AC square wave at an RMS voltage level switching between the values currently set for Voltage 1 and Voltage 2 at the frequency set internally (0.5 Hz to 150 Hz) or triggered externally with 0 to 5 V TTL input (0.1 Hz to 150 Hz). "Switch" mode can also be used to measure the response time of the connected LC retarder.

The LCC25D controller features an additional fast-switching function that allows setting two additional voltages for a total of four voltages that the output can switch between in a cycle. The LCC25D controller also has a heating function with a max set point of 50 °C for temperature-stabilized LC devices, with 0.1 °C resolution. For more information on this controller's operation modes, please see the user manual, which can be found by clicking on the red docs icon () next to the item number below.

The USB (and ethernet for Item # LCC25D) interface can also be used for command-line control so that the LCC25 and LCC25D functions can be automated. This enables operation through a terminal interface or control of the device using a written program.

Thorlabs also offers the compact KLC101 K-Cube^® Liquid Crystal Controller which is part of our growing line of high-end, compact controllers. Multiple K-Cubes can be connected to synchronize output between units, and they also come with their own software for custom sequencing and sweeping operations.

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Figure 3.1  Screenshot of the GUI interface for the LCC25 Controller in Modulation Mode

Software

Version 4.0.1

GUI Interface for controlling the Liquid Crystal Retarder Controller via a PC. To download, Click the button below.

Software for the LCC25 Controller

Graphical User Interface
The graphical user interface (GUI) included with the software provides access to all of the settings of the liquid crystal controller. For example, the user can select one of two user-defined voltages or a modulation mode that oscillates between these two voltages at a user-defined frequency. As shown in Figure 3.1, the GUI includes a plot of the output voltage with respect to time. Both the output and external input can be turned on and off via the GUI. In addition, advanced features allow the user to define a custom waveform by specifying the starting voltage, ending voltage, the voltage step size, and the dwell time. The waveform may be previewed on the screen before it is output to the retarder, and it may be saved so that the LCC25 controller can be restarted quickly in the future. The GUI is available as a stand-alone or LabVIEW based version for flexibility in implementation.

Custom Software Development
Users may also use the provided C/C++ and LabVIEW software development kits for implementing the liquid crystal retarder controller with other instruments. Sample C++ code and LabVIEW programs help to illustrate how the C commands and LabVIEW VIs can be utilized. Full documentation on the available commands is provided with the software.

Click to Enlarge
Figure 3.2  Screenshot of the GUI interface for the LCC25D Controller

Software

Version 1.0.0

GUI Interface for controlling the Dual Channel Liquid Crystal Controller via a PC. To download, Click the button below.

Software for the LCC25D Controller

Graphical User Interface
The graphical user interface (GUI) included with the software provides access to all of the settings of the liquid crystal controller. For example, the user can select one of two user-defined voltages or switch mode that oscillates between these two voltages at a user-defined frequency. As shown in Figure 3.2, the GUI includes controls for each of the two channels independently, including temperature control. Both the output and external input can be turned on and off via the GUI. In addition, advanced features allow the user to define a custom waveform by specifying the starting voltage, ending voltage, the voltage step size, and the dwell time. The waveform may be previewed on the screen before it is output to the retarder, and it may be saved so that the LCC25D controller can be restarted quickly in the future. The GUI is available as a stand-alone or LabVIEW based version for flexibility in implementation.

Custom Software Development
Users may also use the provided C/C++ and LabVIEW software development kits for implementing the liquid crystal retarder controller with other instruments. Sample C++ code and LabVIEW programs help to illustrate how the C commands and LabVIEW VIs can be utilized. Full documentation on the available commands is provided with the software.

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Figure 4.2  Contents Included with the LCC25D Liquid Crystal Device Controller

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Figure 4.1  Contents Included with the LCC25 Liquid Crystal Device Controller

The following items are included in the LCC25 package (Figure 4.1):

• LCC25 controller unit
• USB Type-B Cable
• Region-Specific Power Cord

The following items are included in the LCC25D package (Figure 4.2):

• LCC25D controller unit
• USB Type-B Cable
• Region-Specific Power Cord
• Two 6-Pin Hirose Male to BNC Female Cables
• Ethernet Cable