Abstract: A buried wave guide device is produced by immersing a phosphate glass containing exchangeable ions in a molten salt. Ions are exchanged from the phosphate glass to give a wave guide whose refractive index increases sharply from a first surface to a maximum at a depth below the first surface then decreases gradually in the direction of the opposite surface.

Abstract: A method of producing a gradient-index lens includes a first step in which a glass body is immersed into a molten salt containing ions which are able to provide a refractive index higher than that of ions constituting the glass body, in order to perform ion diffusion into the glass body. Thereafter, in a second step the glass body obtained from the first step is immersed into a molten salt containing ions which provide a refractive index lower than that of the ions of the molten salt used in the first step. In this way there is formed a predetermined refractive index distribution in the glass body.

Abstract: A uniform refractive index-type glass is prepared by ion exchange in which a glass containing ions of a first type is immersed in a molten salt containing ions of a second type, the ions in the molten salt having a higher refractive index than the ions in the glass. The glass is removed from the molten salt at a predetermined point and before the saturation point or equilibrium and the ion distribution becomes uniform throughout the glass. The concentration of first and second ions is not uniform from the center of the glass to its outer surface. The glass is next heated to make the concentrations of the first and second ions substantially uniform throughout the glass from the center to the outer surface. Optionally, this glass is then immersed in a molten salt containing a third type of ion having a lower refractive index than the second ion for exchange with part of the ions in the second type.

Abstract: The refractive index distribution in refractive index distribution lenses may be adjusted to better approach an ideal by heating the refractive index distribution lens. When the refractive index distribution lens was created by diffusion of refractive index changing ions into a body, further heating in an environment in which no additional ions can diffuse into the body causes further migration of ions within the body so that its refractive index distribution approaches an ideal.

Abstract: The present invention provides a gradient refractive index type anamorphic planar microlens which can be utilized for collimating an elliptical beam radiated from a semiconductor laser, or the like, and a method of producing such a lens. To collimate light rays, in which astigmatism exists, it is necessary to use a lens in which the respective focal distances in the directions perpendicular to an optical axis are different from each other. It includes a semiellipsoidal refractive index distribution region formed in a transparent substrate so as to have a major axis and a minor axis on a surface of the transparent substrate.