Boresighting At 830 Nm; Back-Up Solution - Safran LRF 7047 Manual

LRF 7047- Integrator Manual

4.5.2 Boresighting at 830 nm

LRF 7047 is equipped at the factory with an 830 nm pointer. Professional boresighting of the LRF module
with the main optical axis of the host system can be done with the 830 nm pointer. The alignment
procedure is identical to the procedure at 1550 nm, except for the camera. To make the laser spot of 830
nm visible, a regular NIR camera can be attached to the collimator. These cameras are significantly
cheaper than 1550 nm cameras.
The laser pointer is not eyesafe! Appropriate safety measures have to be put in place to use the pointer
for alignment. Keep in mind that the laser pointer is too strong for the camera, for this reason a filter glass
has to be used to attenuate the beam intensity. Please note that the wedge error of the filter has a direct
impact on the alignment accuracy and therefore has to be as small as possible. We recommend using a
filter with a max. wedge error of 10 arcsec.
Filter glass can be sourced, for example, from Schott. Schott Filter glasses KG1, KG2, KG3 or KG5 can
be selected, depending on the required attenuation factor.
http://www.schott.com/advanced_optics/english/products/optical-components/optical-filters/optical-filter-
glass/index.html
If such equipment is not available, the 830 nm pointer can also be made visible by using a Night Vision
device. By using a boresight chart at a defined distance, the LRF can be aligned by bringing the main
optical axis of the host system and the LRF to the predefined positions on the boresight chart.

4.5.3 Back-up solution

If no other optical equipment is available, an alternative method can be
used to show the path of the invisible laser light. Place a vertical and
horizontal small pole (approx. 10 cm of width) at about 200 meters
distance. Start with one orientation (horizontal or vertical) and measure
until the laser hits the pole and gives the correct distance back. You can
then center the laser to this first orientation and then do the same with
the second orientation. With this method you can align the laser to any
equipment, however its more time consuming and not as precise as
with a camera.
A quick and easy tool to make laser light visible are laser viewing cards. These cards have a
photosensitive area which emits a visible spot at the location of the laser beam. However, this only works
when the card is quite close to the LRF module. To see the laser beam of LRF 7047 modules, the laser
viewing card must absorb light of 1550 nm wavelength (or 830 nm if the optional pointer is available).
Vendors of such cards are:
Laser2000 (www.laser2000.de) (e.g. QTX-Q42-T)

Thor Labs (www.thorlabs.de) (e.g. VCR4)

914929_TML_LRF7047_en_Version B
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Figure 15: Boresighting
Public: 04.2019
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