Silica glass member for wavelength conversion, and production method therefor

The invention provides a silica glass member for wavelength conversion for which environmental tolerance, heat resistance, durability and color rendering properties are high, which can be produced using a low-heat process, and which can efficiently convert wavelengths; and a production method therefor. The silica glass member for wavelength conversion is formed by a silica glass substrate and a silica glass surface layer film formed on the surface of the substrate. The silica glass surface layer film is obtained by coating the surface of the silica glass substrate with a polysilazane-containing solution which contains phosphor particles the average particle diameter of which is 0.1 mu m-20 mu m and spherical silica fine particles which are hydrophobic and have an average particle size of 1nm-100nm, drying the coated substrate in the air, and carrying out heating of the same in a water-vapor atmosphere. In the polysilazane-containing solution, the ratio of phosphor particles to the total amount of the polysilazane and phosphor particles is 10:3-7 parts by mass, and the NH group concentration of the silica glass surface layer film is no more than 1000ppm.