What environmental tests have been performed on your gratings?

Our telecom-grade, epoxy sealed gratings have survived boiling water for several days with no degradation and 95° C at saturated humidities for more than 2 weeks. A collapse of the grating structure has been observed after several days at 120° C. Some of our similar, but non-Dickson design, gratings are currently in commercial multiplexers and are surviving real world tests as well as having passed standard compliance testing. The DCG is hermetically sealed between various substrates such as BK-7, Borofloat, low iron sheet glass and fused silica, making it impervious to everything but extreme heat.