Post mortem results of a Laser-Optical system packaged for use in harsh environments

The design and packaging of laser-optical system was tested to harsh environments outside lab conditions and post mortem activities will be discussed. Previously, custom mounts and bonded optical assemblies were environmentally tested to ensure their survivability. The results verified the sub-assemblies would enable the design of a laser-optical initiation system that could be fielded for use in extreme conditions. The design package, which utilized the proven opto-mechanical sub-assemblies, was then tested to the same levels as the sub-assemblies. The test regiment encompassed the harshest environments currently utilized. Temperature tests were performed ranging from a maximum of +75 degrees C to a minimum of -55 degrees C, allowing for two hour soak at each temperature set point. Vibration tests were performed to a maximum level of 15.5 grms for forty seconds in each of three critical axes. Shock tests were performed to a maximum impulse level of 5700 G's for the sub-assemblies with a 1.1 millisecond long pulse; whereas the packaged laser system maximum level reached was 3700 G's at 1.1 millisecond long pulse. The laser-optical assembly was visually inspected and functionally tested before and after each test to verify survival. As designed, the system covers were laser welded shut for hermetic seal. The only open port was the laser output for testing and verification of laser performance. No optical cables were utilized. Therefore the visual inspection of the interior was performed post mortem. The post mortem results will be discussed as will the potential of redesigns on future packaging strategies.