The AEI Hannover optical bench for test of LISA technology before it was integrated in the vacuum chamber. The three lasers are transmitted via optical fibres.
Please visit AEI website for high resoloution image and permission: https://www.aei.mpg.de/57830/a-high-precision-test-bench-for-lisa-techno...
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© D. Penkert/Max Planck Institute for Gravitational Physics