RGB Lasersystems q stick, Руководство пользователя

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Qstick User Manual
4
2.3 Optical Setup
The light enters the Qstick spectrometer through a small slit. 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.
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, use a fiber
optical cable with SMA connector like the one from the Qstick package.
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.
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).
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:
o The focused light is centered on the entrance slit,
o the height of the light spot on the entrance slit is 200 µm or smaller and
o the numerical aperture of your focusing optics is close to 0.07, matching the
numerical aperture of the spectrometer.
If your focusing optics has a larger aperture than 0.07, you loose some intensity inside the
spectrometer. On the other hand, a numerical aperture significantly smaller may lead to a
decrease in resolution.
2.4 Troubleshooting
The green light on the spectrometer is off, the red light is flashing or lit
continuously and the device does not react
This indicates that the device has turned itself off because the USB port was not able to
supply enough power. This also may happen if the USB cable is too long or damaged.
Please disconnect the device and try a different USB port or cable.