Abstract: An optical fiber waveguide is disclosed wherein germanium dioxide (GeO.sub.2) and phosphorus pentoxide (P.sub.2 O.sub.5) are radially graded in the core of the optical fiber for the purpose of achieving minimum modal dispersion over a broad range of wavelengths. The phosphorus pentoxide has its maximum concentration on the axis of the fiber core and is graded to zero concentration at the core-cladding interface. The germanium dioxide has its maximum concentration at the core-cladding interface, is constant throughout the cladding and is graded to zero concentration on the axis of the fiber core. The ratio of maximum P.sub.2 O.sub.5 to maximum GeO.sub.2 is approximately 11.6 and therefore the numerical aperture is only slightly degraded as a result of the reverse doping of germanium dioxide.

Abstract: It is known to form an optical waveguiding thin film on a substrate. For various practical reasons, it is often desired that an optical beam coupled to the film be laterally confined so as to propagate only in a longitudinal stripe portion of the film. As disclosed herein, this is accomplished by depositing spaced-apart elements in contact with one surface of the film to establish in a narrow longitudinal region of the film between the elements an effective index of refraction that is higher than the index of the remainder of the film. In this way a longitudinal waveguiding stripe is formed on the film without the necessity of irradiating, etching or otherwise directly treating the film itself.

Abstract: A tunable permanently fixed diffraction grating is interposed in the path of an optical beam propagated in an integrated-optics device. Tuning is accomplished, for example, by establishing a variable electric field in the propagating medium to control its refractive index. In that way the effective grating spacing is changed. As a result tunable optical filters and intensity modulators are thereby realized.

Abstract: Graded-index fibers, which are the most promising for first-generation optical communication links, are improved for multimode transmission by employing two or more glassy dopants in the core mutually graded with respect to the silica host and to each other to provide simultaneously minimized intermode dispersion at a first-selected wavelength and, in addition, a broader wavelength range of minimized intermode dispersion, or minimized intermode dispersion at a second distinct wavelength pertinent to the multimode transmission, or optimization of another dispersion-related property of said fiber.

Abstract: Electrooptic prism-type deflection is provided in a planar waveguide thin film of electrooptic material, such as a thin titanium-diffused region in a lithium niobate crystal, by means of an electrode arrangement involving three thin metallic stripes as the only needed electrodes. All three stripes are disposed on top of the thin film of light-guiding electrooptic material, the outermost two being essentially parallel to the incoming light beam path, and the third extending diagonally between opposite ends of, but not contacting, the others. The electrooptic material is oriented to have its crystallographic C-axis, along which it exhibits a linear electrooptic effect, parallel to the interface of the light-guiding film and the lower index substrate and othogonal to the initial propagation direction of the light beam. Like deflection voltages are applied to the two triangular electrooptic waveguide portions defined by the stripes.

Abstract: It is known to form an optical waveguiding thin film on a substrate. For various practical reasons, it is often desired that an optical beam coupled to the film be laterally confined so as to propagate only in a longitudinal stripe portion of the film. As disclosed herein, this is accomplished by depositing a material on a selected portion of the film surface to establish in a narrow longitudinal region of the film an effective index of refraction that is higher than the index of the remainder of the film. In this way a longitudinal waveguiding stripe is formed in the film without the necessity of irradiating, etching or otherwise directly treating the film itself.