Abstract: A method and apparatus for measuring nonreciprocal optical effects contemplates directing two circularly polarized optical beams having a known phase relation to each other at a sample, and detecting the difference in phase between the two beams after they have encountered the sample. In a transmission measurement the two circularly polarized beams have the same handedness, but pass through the sample in opposite directions. In a reflection measurement, the two circularly polarized beams have opposite handedness, but encounter the sample in the same direction. In a particular embodiment of the invention a linearly polarized beam is introduced into a Sagnac interferometer and split into two linearly polarized beams which are ultimately recombined.

Abstract: The combination of a resonator having total internal reflection with a coupler providing coupling via frustrated total internal reflection. Both linear and non-linear embodiments are described. The linear embodiment is a spectrum analyzer. The non-linear embodiment is a second harmonic generator, although modifications are described for turning the same into an optical parametric oscillator.

Abstract: A method of growing a single crystal rod with regions of reversed dominant ferroelectric polarities (poling the same) is described. It is a variation of laser-heated pedestal growth. The microscopic growth rate of the crystal is modulated to incorporate into the rod, the compositional melt gradient which is formed at the freezing interface. When this gradient is of the proper sign and the poling action due to it is of sufficient strength to overcome the normal poling action with which the rod would otherwise grow, it defines a reversed domain region. This region is reduced in temperature to below the Curie temperature before the gradient responsible for the same can diffuse. A method of clarifying a single crystal to make the same transparent to optical radiation of interest is also described.

Abstract: An integrated optical waveguide is constructed from a lithium niobate (LiNbO.sub.3) crystal substrate. In preferred embodiments, a diffused layer is formed proximate to one surface of the substrate by sputtering a thin layer of a zinc-related oxide (e.g., ZnO, ZnLiNbO.sub.4, or the like) onto the surface and then annealing the substrate. The resulting concentration of zinc in the diffused layer forms a waveguide having desirable optical propagation characteristics. The substrate is preferably congruent lithium niobate. In particularly preferred embodiments, the substrate is magnesium oxide (MgO) doped lithium niobate.

Abstract: A method of fabricating a waveguide is described minimizing to a desired degree the effect of minor variations caused, for example, during manufacture from an ideal dimension to obtain a coupling of energy between two different frequencies of optical radiation propagated in the waveguide.

Abstract: A nonlinear waveguiding optical converter in a solid state body. The waveguide is provided with compositionally differing region (domains) of dominant electrical polarization in succeeding regions transverse to the path of guided radiation.

Abstract: Optically transparent quantum well structures, such as GaAs/Al.sub.0.5 Ga.sub.0.5 As, are electrically biased to produce a quadratic nonlinear optical susceptibility, the sign of which depends on the direction of the applied electric bias field. This quadratic nonlinear optical susceptibility is particularly useful for enhancing three-wave interactions especially when the applied bias field is made spatially periodic to obtain quasiphasematched interaction. Also, the quantum well material is preferably arranged in an optical waveguide for guiding the interacting waves to reduce unwanted diffraction effects.

Abstract: Changes in the diameter of a fiber are determined by directing a laser beam transversely onto the fiber and directing a fringe produced by the scattering of the beam to a photodiode array by means of a transforming lens. Circuitry is provided to detect movement of the fringe on the diode array thereby indicating changes in the diameter of the crystal fiber.

Abstract: Translation apparatus for a crystal fiber includes a resilient belt which receives a crystal fiber in pressure engagement. The fiber is supported against the belt by a support member having a grooved surface for receiving the fiber. A floating block is positioned within a loop of the belt and is offset in the loop when the support member and fiber are brought into engagement with the belt.

Abstract: Apparatus for growing crystal fibers comprises a housing, a first drive within the housing for supporting and driving a feed rod, and a second drive within the housing for supporting and driving a fiber. Each of the drives includes a vacuum chuck having first and second support surfaces oriented generally perpendicular and defining a line of intersection, a vacuum provided along the line of intersection for retaining either a rod or a fiber in abutment with the first and second support surfaces, and roller means for driving the rod and fiber along the line of intersection. The apparatus further includes a first laser for generating a laser beam and transmission optics for transmitting the laser beam to the housing. Optics within the housing receives and expands the laser beam into a generally annular configuration and focuses the laser beam on an end of the feed rod.