An Nd:glass disc requires an edge cladding to absorb the amplified spontaneous emission. The absorption is determined by reflections (R) from disc edges. R is primarily induced by the refractive index (n) mismatch. Thus, the temperature at the cladding interface increases due to absorption, and leads to the variation of n. In order to investigate the effect of temperature on the refractive index match, temperature coefficients (dn/dT) of the laser glass, adhesive polymer, and cladding glass are measured. The effect of temperature on the refractive index match is discussed. Results show that the indices match below 40 °C.