NOVELTY - A solid-state optical device (1) consists of a solid-state element (2), a power supplying/retrieving portion (4), and a glass sealing material (6). The power supplying/retrieving portion supplies or retrieves electric power to/from the element. The glass sealing material has a thermal expansion coefficient equivalent to that of portion (4). The glass sealing material comprises a phosphorus pentoxide-alumina-zinc oxide-based low-melting glass comprising (in wt.%) phosphorus pentoxide (55-62), alumina (5-12), and zinc oxide (20-40).    USE - Solid-state optical device, such as wavelength conversion type light-emitting device, light receiving element, and solar cell element.    ADVANTAGE - The solid-state optical device has excellent sealing properties provided by a sealing material of low-melting glass, reliability, and moisture resistance. Opacity of glass material in sealing and white turbidity of glass material in evaluation of the characteristics, are prevented. Tight mounting of optical elements can be achieved. The entire device is constructed by a material with low thermal expansion coefficient. A compact package can be realized even with respect to a small bonding area. The solid-state optical device uses a substrate having high thermal conductivity and good bonding strength with respect to the glass sealing material. Hence, the device is well suited for high light intensity and high output type light-emitting devices.    DETAILED DESCRIPTION - A solid-state optical device consists of a solid-state element, a power supplying/retrieving portion on which the solid-state element is mounted, and a glass sealing material which seals the solid-state element. The power supplying/retrieving portion supplies or retrieves electric power to/from the solid-state element. The glass sealing material has a thermal expansion coefficient equivalent to that of the power supplying/retrieving portion. The glass sealing material comprises a phosphorus pentoxide-alumina-zinc oxide-based low-melting glass comprising (in wt.%) phosphorus pentoxide (55-62), alumina (5-12), and zinc oxide (20-40). The low-melting glass further comprises boria (0-5), lithia (0-3), sodium oxide (0-3), potassium oxide (0-3), magnesium oxide (0-5), calcium oxide (0-10), strontium oxide (0-10), barium oxide (0-20), niobium oxide (0-20), titania (0-20), bismuth oxide (0-20), gadolinium oxide (0-5), tungstic oxide (0-5), and zirconia (0-5).    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a light-emitting device as solid-state optical device.    Solid-state optical device (1)    Solid-state element (2)    Substrate (3)    Power supplying/retrieving portion (4)    Glass sealing material (6)