Optical Interface; Coatings; Isolation Of Optical Channels; Environment - Safran LRF 6042 Manual

LRF 6042 Integrator Manual

5 Optical interface

The LRF emits laser light from the transmitter lens of the following wavelengths:
 1550 nm for range measurements
 830 nm for pointer functionality (if available)
In order for the LRF to work properly, the front design of the host system must allow the transmission of both
wavelengths.
NOTICE
It is best practice and highly encouraged recommendation to:
 use two isolated optical channels separated from each other;
 each of them with its own set of windows;
 use a tilt angle on the front windows of 5° - 10°;
 both windows should be sufficiently parallel to each other;
 both windows should be sufficient flat and straight (avoid convex, concave or prism shapes)
 apply an appropriate coating for both sides of both windows;
Not observing these directives, does not necessarily imply a defective design.
Other options are possible if the system integrator takes the necessary measures.
A defective design may originate:
 destruction of the module (ex. full laser energy is mirrored back by a perpendicular window);
 cross talk (scattered laser light from transmitter to receiver), which originates massive range
performance reduction, incorrect or no measurements;
 reduction of performance with a not optimal or no coating;
 optical mirror (ex. sunlight reflections to the target/enemy)

5.1 Coatings

The coating of the front windows shall fulfill the following specifications:

Visible light: R < 1 % for λ = 420 ... 650 nm, light angle 0°+/- 15° for both lenses.

Measurement light: R < 0.5 % for λ = 1'500 ...1'600 nm, light angle 0°+/- 15° for both lenses.

Optional pointer light: R< 0.5 % for λ = 790...870 nm, light angle 0°+/-15° for transmitter lens.
*Please refer to Appendix 11.3 Reference design for lenses as an example.

5.2 Isolation of optical channels

The use of EPDM L 7510 material is recommended for optical isolation. This prevents cross talk (scattered
laser light from transmitter to receiver)
*Please, refer to Appendix 11.5 Reference design for optical isolation as an example.

5.3 Environment

The LRF module is not gas tight. Therefore installing an LRF module into a host system requires a protective
environment with a window in front of the LRF module.
INTEGRATOR MANUAL LRF 6042 917657- A
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Public: 02.2022
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