| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical element having glass not containing alkali metal oxides as essential components and ensuring a small change in light path due to temperature changes as a component. SOLUTION: The optical element is used for light of 450-1,700 nm wavelength and has glass through which the light should propagate as a component or comprises glass through which the light should propagate, wherein dS/dT(=dn/dT+nα) expressed using the refractive index n of the glass to light of 1,550 nm wavelength, the rate dn/dT of temperature change of n at 25°C and the coefficientαof linear expansion at 25°C is≤8.9×10<SP>-6</SP>/°C and the glass contains≤1 mass% alkali metal oxides. COPYRIGHT: (C)2004,JPO |
