Slumping of optical surfaces takes place while antireflection substrates are being coated at 205°C. Greater slumping is experienced at higher temperatures. Optical glasses held in kinetic-designed holders exhibit variable memories of reslumping. Glass elements held in nonkinetic and kinetic holders are compared at 205°C.
A. S. De Vany, "The Slumping of Optical Surfaces during Coating," Appl. Opt. 5, 735-736 (1966)