Abstract: An electro-optic modulator is described which uses periodic inverted domain regions to permit it to be able to handle high powered optical light.

Abstract: A frequency converting laser device includes a plurality of laser diodes each adapted to produce an output laser light beam and a plurality of optical fibers, each coupled to the output of a corresponding laser diode and including a built-in grating in the optical fiber arranged so as to provide a beam having a specific wavelength and to reflect a small portion of such beam back into the laser diode while transmitting the beam so that the laser diode will produce a beam of that wavelength. The device further includes frequency converting structure adapted to receive the transmitted beams of laser light and to change the frequency of each input beam to produce output beams at desired frequencies.

Abstract: A method for forming inverted ferroelectric domain regions in a substrate including ferroelectric material and having two major opposite surfaces. The method includes application of controlled electric field in selected regions to inhibit subsequent nucleation and growth of selected domains; applying a conductive electrode over the opposite major surfaces; and providing a voltage to the conductive electrodes having a sufficient magnitude and duration to cause the ferroelectric polarization to invert in selected unmodified regions.

Abstract: A method of forming ferroelectric domain regions in a ferroelectric crystal cut so that the polarization direction is in the plane of the crystal and is along the z direction is disclosed. The method includes forming a conductive ground electrode on the surface of the plane and having an edge perpendicular to the z direction or the polarization direction in the crystal plane; and electron beam bombarding the plane of the crystal in particular spots to deposit a charge such that the electric field created between the edge of the electrode and the spots is in a direction opposite to the crystal polarization direction and causing the inversion of the crystal polarization direction between the charge spot and the electrode.

Abstract: Ferroelectric domain regions are formed in a ferroelectric crystal cut so that the polarization direction is in the plane of the crystal and is along the z direction is disclosed. A periodic ion exchange grating on the surface of the crystal with grating is provided on the surface of the crystal with grating lines parallel to the Z-axis of the crystal by a combination of photolithography and ion-exchange techniques and then applying a uniform field across two electrode pads on the crystal surface, thus creating an electric field opposite to the polarization direction (+Z direction) of the crystal. The electric field reverses the domains in selective regions defined by the ion exchange grating formed in the earlier step. This gives rise to a periodically reversed domain grating on the crystal surface.

Abstract: An integrated frequency conversion and scanner for converting the frequency of an input light beam and deflecting the converted light beam through an electronically controlled angle is disclosed. This structure includes an electrooptic crystal including a region formed for converting the frequency of the input light to a higher frequency; and a field changing structure associated with selected regions of the crystal arranged so that an electric field is created at least partially within the crystal to change its refractive index to thereby deflect the converted light beam through an electronically controlled angle.

Abstract: A ferroelectric light frequency doubler device has a surface coating on one surface of an initially uniformly poled ferroelectric crystal, the surface coating on the one surface being exposed to a scanning electron beam so as to form a spatially periodically alternating polarity domain structure in the crystal. The surface coating can be of an inorganic material or it can be of a polymeric organic material. The surface coating can be adapted to be patterned to form an optical grating in registrative alignment with the spatially periodically alternating polarity domain structure when such optical grating is desired. Alternatively, the surface coating may remain on the device as a protective coating, or it may be removed upon formation of the alternating polarity domain structure in the crystal.

Abstract: A frequency converting laser device is disclosed which includes a laser diode adapted to produced an output laser beam and an optical fiber coupled to the output of the laser diode and including a built-in grating in the optical fiber arranged so as to provide a beam having a specific wavelength and to reflect a small portion of such beam back into the laser diode while transmitting the beam so that the laser diode will produce a beam of that wavelength. The device further includes a frequency converting structure adapted to receive the transmitted beam of light and to change the frequency of the input beam to produce the output beam at the specific frequency.

Abstract: Optical reproducing apparatus utilizes a dual diffraction grating having first and second diffraction gratings with the diffraction gratings oriented at an angle with respect to one another to polarize an incident return beam into TM and TE components. TM and TE components emerge from the dual diffraction grating at a slight angle with respect to one another and are focused on a photodetector chip by an objective lens. In accordance with a first specific embodiment of the apparatus, the TM and TE polarized components are focused directly on a photoelectric chip, with the TE component focused on a spot size focus detector comprised of three rectangular photoelectric elements. One photoelectric element is disposed between the other two with a pair of parallel interfaces. Disturbances introduced into the TE beam are in the direction of the parallel interfaces, rendering the spot size focus detector wavelength-insensitive.

Abstract: A method of making an optical device including a semiconductor laser and a waveguide optically coupled to the laser, includes the steps of providing a substrate formed from a material on which a semiconductor laser can be created; sequentially creating a plurality of layers of relatively different impurity types and concentrations on the substrate, to form a laser structured region; forming a first mirror at one edge of the laser structured region; removing a portion of the laser structured region opposite the one edge by etching the region to a preselected depth selected so that a waveguide mounted on the substrate in the etched region is vertically aligned with a light emitting portion of the laser structured region; and forming a second mirror on the edge of the laser structured region opposite the first edge and adjacent the etched portion.

Abstract: A surface relief reflection diffraction grating is used as a wavelength compensating element for a diffraction grating coupler. The changes in wavelength are compensated for by adjusting the parameters of the reflection diffraction grating so that the dispersion of the reflection diffraction grating is generally equal and opposite to the dispersion of the diffraction grating coupler. The technique has been shown to permit the range of wavelengths which can coupled with the diffraction grating coupler to be extended from 0.7 nm to 17 nm. The lateral shift has an important contribution and can be limiting factor in wavelength compensation.

Abstract: A frequency converter/mixer has a crystalline substrate which supports an inorganic, crystalline, nonlinear optical thin film having a higher index of refraction than the substrate, to form an optical waveguide. Input radiation of frequency .omega..sub.1 which enters the waveguide propagates through the waveguide and exits as radiation having a different frequency .omega..sub.2. The frequency conversion of the input radiation is accomplished by first-order quasi-phase-matching the input and output signals as a result of the periodicity of the sign-alternating nonlinear dielectric susceptibility coefficient of the optical thin film over an active region of the waveguide. A method of first-order quasi-phase-matching is also disclosed.

Abstract: In the read/write head of an optical storage system, a bi-direction grating coupler is used to replace optical components normally found in the read/write head. The use of the bi-directional grating coupler reduces the bulk and weight of the read/write head. The two channels of the bi-directional grating coupler can be used to separate a radiation component that can used to provide a tracking control signal from a radiation component that can be used to provide a focus control signal. One of the channels is also used to provide the radiation component from which the data on the storage medium can be identified. The bi-directional coupler can be implemented by two grating couplers, each grating coupler having a thin film associated therewith and each grating coupler diverting a selected radiation portion into the associated thin film.

Abstract: An optical head is disclosed in which a beam from a diode laser is directed onto an optical disc, and a beam reflected from the optical disc is passed through an optical device which forms a plurality of discrete beams of different orders. The beams from the optical device are focussed onto photodetectors, and signals from the photodetectors are used for error detection, tracking, and signal detection. The optical device comprises two diffraction gratings which are supported on a substrate and are separated from each other by a thin film. In order to obtain the advantages of a doubly-periodic structure, the thickness of the thin film between the two gratings is very accurately controlled to be on the order of the wavelength of the incident beam of radiation.

Abstract: A hybrid, thin-film, optical waveguide structure has a substrate with a grating coupler formed thereon. A thin-film waveguide film is formed on the substrate and has a tapered portion overlaying the grating.

Abstract: An apparatus for recording onto and reading from an optical disk includes an array of laser diodes that emit a plurality of laser beams with each beam at the diode source spaced a distance greater than about 50 .mu.m from adjacent beams. The apparatus includes a plurality of channel waveguides coupled to the plurality of laser diodes with each channel waveguide associated with a respective laser diode for directing light emitted by the diodes toward the optical disk for optical recording and for receiving reflected light from the optical disk for reading the optical disk. Each beam emanating from the channels is spaced from adjacent beams a preselected distance less than about 50 .mu.m.

Abstract: An optical device is disclosed for diffracting an incident beam of radiation to form a plurality of discrete diffracted beams of different orders. The optical device comprises two diffraction gratings which are supported on a substrate and are separated from each other by a thin film. In order to obtain the advantages of a doubly-periodic structure, the thickness of the thin film between the two gratings is very accurately controlled to be on the order of the wavelength of the incident beam of radiation.

Abstract: A method is disclosed for making an optical device which is adapted to diffract an incident beam of radiation to form a plurality of discrete diffracted beams of different orders. The optical device comprises two diffraction gratings which are supported on a substrate and are separated from each other by a thin film. In order to obtain the advantages of a doubly-periodic structure, the thickness of the thin film between the two gratings is very accurately controlled to be on the order of the wavelength of the incident beam of radiation.

Abstract: Optical recording elements having metal reflective layers which are coated on both sides with a ceramic overcoat are disclosed.

Abstract: A recording element comprising a support having thereon a heat-deformable optical recording layer having a transparent ceramic overcoat characterized in that the overcoat has a thickness up to about 0.05 .mu.m is disclosed.