Ocean Optics RSS-VA User Manual

RSS-VA

Variable-angle Reflection

Sampling System

Installation and Operation Instructions

Description

The RSS-VA Variable-angle Reflection System is an optomechanical device that couples to
spectrometers and light sources to measure the specular reflection of optical substrates from 200­1100 nm, at varying angles of incidence.

The RSS-VA features two SMA 905 Connectors – one to illuminate the sample and one to collect the
reflected light and transfer it to the spectrometer. It also features a 3-point surface mount that holds the
sample to be measured in a fixed position during the integration period.

Inside the black anodized chamber, the RSS-VA features optics mounted on a carrier that you can
manually adjust to set the angle of incidence from approximately 10
thumbscrew holds the optical assembly at the fixed angle.

When used with Ocean Optics spectroscopic systems and specular reflectance standards, the RSS-VA
is a versatile variable-angle device for characterizing a variety of optical substrates, such as those
featuring metallic and dielectric coatings.

° to 50°. Once adjusted, a

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RSS-VA Installation and Operation Instructions

How the RSS-VA Works

The RSS-VA features a unique internal design that enables it to obtain sample measurements at
varying Angles Of Incidence (AOI). The RSS-VA works as follows:

Light enters the RSS-VA via the SMA 905 input connector (1).

1. Light is reflected up onto the sample port (2) at the degree determined by the AOI setting on
the RSS-VA, where it interacts with the sample.

2. Sampled light is reflected back down through the RSS-VA.

3. Light exits the RSS-VA via the SMA 905 exit connector (3).

Assembling the Hardware

You must first configure your sampling hardware and the RSS-VA prior to measuring your sample.

► Procedure

Follow the steps below to set up the RSS-VA:

1. Connect a fiber from the light source to the SMA 905 input connector of the RSS-VA.

2. Connect a fiber from the SMA 905 output connector of the RSS-VA to the spectrometer.

3. Place a STAN-SSH standard on the sample port.

4. Start your spectrometer operating software. Once data acquisition begins, a typical bell­shaped curve should be displayed in the graph area.

5. Adjust the position of the slide carrier on the RSS-VA until the pointer on the RSS-VA is at
the desired AOI.

6. Adjust the integration time in the software until the signal peaks at approximately 3500
counts.

You have now properly configured the RSS-VA hardware.

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RSS-VA Installation and Operation Instructions

Using the RSS-VA with Spectrometer Operating Software

Standard files are included with your Ocean Optics spectrometer operating software. These text files
have a *.STANDARD file extension.

Using SpectraSuite

► Procedure

Follow the steps below to set up the software for use with the RSS-VA with SpectraSuite:

1. Start the SpectraSuite software, if necessary.

2. Set up your experiment as usual by choosing the appropriate integration period (so the signal­to-noise will be high but the spectra or samples won’t be off scale). Choose scans to average
and box car smoothing to obtain the desired signal-to-noise ratio.

3. Store the dark and reference spectra and switch to %R (or %T) scales. SpectraSuite will make
your graph read 100% +/- random noise across the spectra.

4. Click on the
must be exactly as expected or SpectraSuite won’t be able to load it properly. Once you load
the file, the contents of the file header are shown as well as a graph of the reflectivity values.

5. Click the
interpolated to the wavelength at each pixel. You can take a new Reference spectrum at any
time without having to go through the wizard again.

See your SpectraSuite manual for more information about performing a reflectance experiment.

Apply button to make your stored reference read the values from the file,

icon. The wizard asks for the location of the standard file. The file format

Using OOIBase32

► Procedure

Follow the steps below to set up the software for use with the RSS-VA with OOIBase32:

1. Start the OOIBase32 software, if necessary.

2. Select

3. Enable the check box next to the

4. Navigate to and select the standard file in the OOIBase32\Standards directory. The standard

Spectrum | Configure Standard Selection from the OOIBase32 menu bar. The

Configure Standard Selection dialog box appears.

Enable Standard Correction option, and then enter the AOI

setting on the RSS-VA into the

information is loaded into OOIBase32.

Reflection AOI box.

5. Click the

6. Place the STAN-SSH or STAN-SSL standard on the sample port. Ensure that the standard is
mounted properly on the 3-point mount and that it is not tilted.

7. Store a reference spectrum in OOIBase32.

8. Turn the light source off and store a dark spectrum in OOIBase32. The system is now
normalized.

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OK button to store these inputs and close the dialog box.

RSS-VA Installation and Operation Instructions

Note

When using a transparent sample with the RSS-VA, ambient light may enter the
sample port when attempting to take a spectrum. In this scenario, place the screw-on
cap of the standard over the sample port (on top of the sample) to block the ambient
light from entering the sample port. Then, block the light path and store a dark
spectrum as you normally would.

9. Click on the R icon in OOIBase32 to enter Specular Reflectance mode.

10. Place the sample on the sample port and measure the reflectance at the desired AOI
(configured in Step 5 of the

Using the RSS-VA with Spectrometer Operating Software section,

above). Ensure that the sample is mounted properly on the 3point mount and that it is not
tilted.

Note

If you adjust the AOI of the RSS-VA, you must re-normalize the spectrometer.
Perform Steps 1-3 in the Taking Measurements Using the RSS-VA section above, and
ensure that the peak signal in the OOIBase32 graph window is at approximately 3500
counts.

Specifications

Dimensions: 1114.3 mm x 41.3 mm x 101.6 mm

Weight: 980 g

Sample port: 19.0 mm x 6.4 mm

Connectors: (2) SMA 905 (for illumination fiber & read fiber)

Surface mount: 3-point

Angles of incidence: ~10° to ~50° (user-adjusted)

Wavelength range: 200-2000 nm

Recommended optical fiber: Ocean Optics 100 µm Laboratory-grade Optical Fiber

Material: Black anodized stainless steel

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