Rgb Lasersysteme QWAVE UV Lux-Meter, illumination measuring device, Brightness meter, DSA491006 Datenbogen
Produktcode
DSA491006
Qwave User Manual
4
without connecting an actual device. You can access this dialog window later on by
choosing “Device Setup” from the File menu.
choosing “Device Setup” from the File menu.
2.2 Optical Setup
The light enters the Qwave spectrometer through a 20 µm slit (other slits are available as
custom modifications). You can see this slit if you look into the fiber optical connector on
the front side of the device.
custom modifications). You can see this slit if you look into the fiber optical connector on
the front side of the device.
If the light you wish to measure is quite strong, you may simply point the spectrometer
towards it. For example, you can test the spectrometer by pointing it towards your
computer screen or your desk light.
towards it. For example, you can test the spectrometer by pointing it towards your
computer screen or your desk light.
In most cases, however, you’ll need a special optical probe to collect as much light as
possible. In order to guide the light from the probe to the spectrometer, most users
prefer a simple fiber optical cable with SMA connectors. Alternatively, you may also focus
the light directly onto the entrance slit without fibers using your own optics.
possible. In order to guide the light from the probe to the spectrometer, most users
prefer a simple fiber optical cable with SMA connectors. Alternatively, you may also focus
the light directly onto the entrance slit without fibers using your own optics.
We recommend standard fiber optical cables with a core diameter of 200 µm and a small
numerical aperture. If you’re using a fiber with a smaller diameter, you’ll get a slightly
better resolution and sensitivity, but you may find it more difficult to focus the light into
the fiber. If you’re using a larger fiber, the spectrometer cannot detect all of the light
coming out of the fiber and the stray light is slightly increased.
numerical aperture. If you’re using a fiber with a smaller diameter, you’ll get a slightly
better resolution and sensitivity, but you may find it more difficult to focus the light into
the fiber. If you’re using a larger fiber, the spectrometer cannot detect all of the light
coming out of the fiber and the stray light is slightly increased.
PLEASE NOTE: The calibration for the spectral sensitivity correction and the optical
power was made with a 200 µm fiber optical cable. If you use a different fiber or
especially if you just point the spectrometer towards the light source, the measured
spectrum might not be accurate. If you have a calibrated light source, you can always
recalibrate the spectral sensitivity for any optical setup (see chapter 3.9).
power was made with a 200 µm fiber optical cable. If you use a different fiber or
especially if you just point the spectrometer towards the light source, the measured
spectrum might not be accurate. If you have a calibrated light source, you can always
recalibrate the spectral sensitivity for any optical setup (see chapter 3.9).
If you focus the light directly onto the entrance slit, you’ll get the best sensitivity and
lowest stray light if you make sure that:
lowest stray light if you make sure that:
• The focused light is centered on the entrance slit,
• the height of the light spot on the entrance slit is 200 µm or smaller and
• the numerical aperture of your focusing optics is close to 0.1, matching the
• the height of the light spot on the entrance slit is 200 µm or smaller and
• the numerical aperture of your focusing optics is close to 0.1, matching the
numerical aperture of the spectrometer.
The Qwave spectrometer does not detect light from outside a cone that corresponds to a
numerical aperture of about 0.1. Therefore, if your focusing optics has a larger aperture,
you loose some intensity inside the spectrometer. On the other hand, numerical
apertures significantly smaller than 0.1 may lead to a decrease in resolution.
numerical aperture of about 0.1. Therefore, if your focusing optics has a larger aperture,
you loose some intensity inside the spectrometer. On the other hand, numerical
apertures significantly smaller than 0.1 may lead to a decrease in resolution.