Download EOM - Contrast Ratio Measurement

EOM Quick Start Manual: Contrast Ratio Measurement, Normal Incidence
This document is intended as a quick start manual for doing Contrast Ratio at normal angle of
incidence. It will describe the most common hardware configuration and the most common parameter
settings chosen by most users. If you require assistance for other hardware configurations or
additional parameter selections, please review the full EOM Manual that comes with the EOM
software installation.
Required Hardware:
1. Computer with EOM Software ver 5.11 or higher and Internal National Instruments Data Acquisition
Card model PCI-6071E.
2. National Instruments External BNC-2090 Shielded BNC Adaptor Chassis
3. Power Source for Light Source is Oriel Fiber Optic Illuminator MN 77501
4. Oriel Light Source is model 60020
5. Signal Amplifier (if more than 10 V output required)
6. Coaxial cables (1 short jumper, 1 long input, 1 long output with split out leads for sample)
7. All related data and power cables.
8. Detector: Oriel model 71882 (or any analog output detector with 0 to 10 or -5 to +5 V range)
Your hardware setup should be as follows:
1. EOM software is installed on PC
2. OceanOptics card is installed in PC and drivers loaded
3. Big data cable goes from PC card to National Instruments external signal board (data cable port on
external board is switched to MIO-16)
4. National Instruments external board has ACH0 connected by coaxial cable to detector output
(Coaxial input ACH0 is switched to SE)
5. National Instruments external board has DAC0OUT connected to a split coaxial for attaching leads to
samples
6. National Instruments external board has DAC1OUT and PF10/TRIG1 jumpered with short coaxial
cable
7. Power source for lamp is plugged into lamp and gets AC power from the wall
8. Oriel lamp gets power from the power source
9. IR filter is installed in front of light source
10. Attenuators (Neutral Density Filters) need to be used (if necessary) to knock down detector voltage to
less than 10 volts
11. Detector has AC power to wall plugged in
The Optical Board should be set up as follows:
1.
2.
3.
4.
5.
6.
7.
Light Source
IR filter (Edmund Optics model 45648, heat absorbing glass, 50mm round)
Neutral Density Filter(s) (if required, Edmund Optics models NT47-207, 208, 209; 25mm round)
Polarizer (if sample does not have them attached)
Sample Holder connected to drive leads from DAC0OUT
Polarizer (if sample does not have them attached)
Detector
Rev 1.0 5/11/2007 BWall
Turning on Hardware:
1.
2.
3.
4.
5.
Turn on computer.
Turn on power for light source (lamp needs 30 minutes to stabilize)
Attach leads from DAC0OUT to sample
Attach sample to Sample Holder
Open up EOM software
Making the Contrast Ratio Measurement:
NOTE: This procedure is for Contrast Ratio measurement at normal incidence (no stepper motor needed):
1. Select Static Response from main software menu
2. Click on the button, Configure Waveform Driver
a. Click on the button, Load Waveform
b. Select ‘asquare.wfm’ from the list
c. Click on the button, Load
d. In the parameter area Drive Mode, select Fixed Number
e. In the parameter area Waveform reps/sec, type in the frequency of measurement you want
(about 1 kHz is default)
f. In the parameter area State 1, type in the drive voltage you want for one of the two LCD states
(fully ON or fully OFF)
g. Click on the button, Turn Waveform On
h. Click on the button, Quit
3. Click on the button, Configure Detector Driver
a. Click on the button, Load Detector
b. Select ‘Chan0_Rse_unipolar.det’ from the list
c. Click on the button, Load
d. In the parameter area Acquisition Parameters, under the section, Data Mode, select
‘continuous’
e. Click on the red button that says “Detector OFF” (it will turn green and change to “Detector
ON” and detector energies will be seen in real time. Make sure the value is under 10. If not,
use Neutral Density Filters to drop the energy down under 10 for the state that passes the
highest amount of energy.
4. With sample in place, set the voltage in section 2. above to one of the drive state voltages and record
the output intensity in section 3. above. Then switch the voltage in section 2 to the other drive state’s
voltage, and record the output intensity of that voltage state in section 3.
5. Take the output intensity of the bright state (high intensity state) and divide by the output intensity of
the dark state (low intensity state) and this is the contrast ratio at normal incidence.
Rev 1.0 5/11/2007 BWall
DATE:
Voltage
ON
NAME:
Voltage
OFF
Rev 1.0 5/11/2007 BWall
Frequency
Energy of
Bright State
Energy of
Dark State
CR
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