Coatings for special applications
Operating a laser system under high-vacuum conditions in space requires environmentally robust coatings and optics.
The key risk factors for failure are laser-induced contamination and coating degradation. You have to exclude increasing absorption, coating destruction or delamination due to cosmic, solar or laser radiation before sending out flight optics.1)
In various projects2) for DLR, ESA and NASA or their industry partners, LASEROPTIK has developed coatings and optics for laser applications in space or airborne environments and proven their functionality and durability.
MS and IBS coatings withstand extreme temperature ranges and working conditions required for airborne laser optics. Additionally, we test the resistancy of specific coatings against gamma and neutron radiation for use in space. Environmental testing can be done by LASEROPTIK or one of our partner institutes.
As part of the extensive qualification program, laser optics and coatings underwent several LIDT tests with simulated space conditions. DLR and LZH3) performed for example damage tests under vacuum conditions. See below for the results for an UV space laser HR 355 nm/s HT 532 nm/p + 1064 nm/s /45° with an AR on the rear surface, measured in vacuum:
LIDT with 10,000 on 1 LIDT, vacuum 2 x 10-6 mbar, repetition rate 100 Hz.
Pulse duration: 3 ns (355 nm); 6.5 ns (532 nm);
12 ns (1064 nm).
Beam diameter: 160 µm (355 nm); 280 µm
(532 nm); 310 µm (1064 nm).
References and further reading:
1) Wernham, D. (2011): Optical coatings in space, in: Proc. SPIE 8168, Advances in Optical Thin Films IV, 81680F (04. Oct. 2011).
2) Cosentino, A.; Selex Galileo S.p.A., Rome, Italy; D'Ottavi, A.; Sapia, A.; Suetta, E.: Spaceborne lasers development for ALADIN and ATLID instruments, Geoscience and Remote Sensing Symposium (IGARSS), 2012 IEEE International
3) Riede, W.; Allenspacher, P.; Lammers, M.; Wernham, D., Ciapponi, A.; Heese, C.; Jensen, L.; Maedebach, H.; Ristau, D. (2013): From ground to space: How to increase the confidence level in your flight optics, in: 45rd Annual Laser Damage Symposium on Optical Materials for High Power Lasers, 8885. SPIE Laser Damage, 22.-25. Sep. 2013, Boulder, USA.
Every coating type can be optimized
• substrate material
• angle of incidence
• GDD value
Alternatively we can create
a totally new design for you.