In large laser systems such as NOVA at Lawrence Livermore National Laboratory, active laser glass is surrounded by a cladding glass, the purpose of which is to absorb 1.06um laser light and prevent parasitic laser action from occurring due to amplified spontaneous emission (ASE). Currently, the cladding glass utilizes the base composition equivalent to the active laser glass with copper doping. Copper produces the required absorption coefficient, approximately 2.8/cm. The cladding glass has a high coefficient of thermal expansion which results in the degradation of optical properties of the laser disc due to thermally induced strain. To eliminate this problem the concept of a near zero expansion glass ceramic cladding material was developed.
