Abstract: In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped yttrium aluminum oxide material). The optical input signals include optical signals having wavelengths over a range of at least 80 nanometers, and, preferably, over a range of at least 160 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over the extended 80-160-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end or the range.

Abstract: In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped yttrium aluminum oxide material). The optical input signals include optical signals having wavelengths over a range of at least 80 nanometers, and, preferably, over a range of at least 160 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over the extended 80-160-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end or the range.

Abstract: A method for fabricating periodically poled structures. The method produces an electric field within a ferroelectric substrate by applying a voltage waveform to an electrode structure disposed on a surface of the substrate. The waveform raises the electric field magnitude to a level substantially greater than that required to reverse domains within the substrate. The waveform then lowers the voltage such that the electric field has a value at which a domain wall velocity is most sensitive to changes in the field. The waveform maintains the electric field value until a current through the substrate drops substantially. The electric field is then lowered to a value below a level required to sustain domain wall motion, but greater than a level below which backswitching occurs. The electric field is then lowered to zero in such a way as to prevent backswitching.

Abstract: A method for fabricating periodically poled structures. The method produces an electric field within a ferroelectric substrate by applying a voltage waveform to an electrode structure disposed on a surface of the substrate. The waveform raises the electric field magnitude to a level substantially greater than that required to reverse domains within the substrate. Domain reversal continues through to completion at which time the poling field is turned off or substantially reduced to induce spontaneous backswitch poling. The forward poling field is then reapplied to stop the backswitch poling. The ability to selectively enable and terminate backswitching allows for the formation of domain patterns with small feature sizes and high uniformity through large volumes of material.

Abstract: In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous material (e.g., erbium-doped yttrium aluminum oxide material). The optical input signals include optical signals having wavelengths over a range of at least 80 nanometers, and, preferably, over a range of at least 160 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals. The optical gain causes the optical signals to be amplified within the waveguide to provide amplified optical signals over the extended 80-160-nanometer range, including, in particular, optical signals having wavelengths at one end of the range and optical signals having wavelengths at a second end or the range.

Abstract: In a method of amplifying optical input signals over a wide bandwidth, the optical input signals are applied to an optical waveguide made from a rare-earth-doped amorphous yttrium aluminum oxide material (e.g., erbium-doped yttrium aluminum oxide material). The optical input signals include optical signals having wavelengths shorter than 1,520 nanometers and optical signals having wavelengths longer than 1,610 nanometers. Preferably, the wavelengths range from as short as approximately 1,480 nanometers to as long as approximately 1,650 nanometers. Pump light is applied to the optical waveguide to cause the waveguide to provide optical gain to the optical input signals.

Abstract: A compensated nonlinear optical frequency mixer for compensating the walk-off produced by group velocity mismatch (GVM) between interaction waves. The compensated mixer has a first mixing region in which the interaction waves participate in a non-linear optical mixing process and where walk-off occurs between the interaction waves due to GVM. The compensated mixer is equipped with a frequency selective coupling and time delay structure located after the first mixing region for eliminating the walk-off produced between the interaction waves in the first mixing region by guiding the waves in arms whose lengths differ by a re-synchronization length. A second mixing region is located after the frequency-selective coupling and time delay structure, such that when the waves emerge in phase from the frequency selective coupling and time delay structure they continue to interact efficiently in the second mixing region.

Abstract: A method for fabricating gallium arsenide (GaAs) based structure groups with inverted crystallographic orientation to form wavelength converters that utilizes germanium as a crystallographic neutral template layer deposited on a GaAs substrate. A crystallographic inverted gallium arsenide layer is grown on top of the template layer. In a selective trench etching process areas of the substrate are exposed again for a consecutive collective deposition of GaAs.

Abstract: A method of patterning domains within a body of a ferroelectric material includes the application of an electric field thereto via spaced conductors. Prior to applying the electric field to the material effects on the patterning of the existence of fringe electric field components which will be created in said body by said application of an electric field, surface treatments, and relative geometries of the body and the conductors are examined.

Abstract: A method of domain patterning a body of ferroelectric material in which the effects of the materials which interface with the body are selected to provide selected characteristics to the domain pattern.

Abstract: Devices for increasing the power handling capability through increased aperture size of patterned poled nonlinear optical material are disclosed. One embodiment employs a prism bonded to the top surface of a plate (a surface parallel to the plate) of poled material. The faces of the prism provide entrance and exit windows for light. Light enters the prism, enters the first surface of the plate at a small angle, reflects from the bottom surface of the plate and then exits the device through the prism exit window. The plate exerts a nonlinear effect on the light. Higher power handling is achieved because, compared to prior art techniques, the light is spread over a larger area in the poled plate. A second embodiment provides for the same advantages by bonding several plates to form a single unit. The plates are stacked, aligned, and bonded together. The result is a single unit with a larger aperture and therefore higher optical power handling capability than is possible with a single plate.

Abstract: A method of domain patterning a body of ferroelectric material is disclosed. This method includes patterning the surface of the material with conducting strips for applying an electric field of desired configuration to said body and covering the conductive strips and surface of the body with insulating material to control the fringe electric field components in the body of ferromagnetic material.

Abstract: A chirped pulse amplification system employs chirped quasi-phase-matched (QPM) gratings as dispersive delay lines for stretching and/or compressing ultrashort pulses. QPM gratings with periods varying along the beam propagation direction produce simultaneous second-harmonic generation and, in general, both amplitude and phase modulation of this second harmonic output. The aperiodic QPM gratings are designed to provide stretching or compression of the output second harmonic pulse with respect to the fundamental-wavelength input pulse. The chirped QPM gratings are also used for simultaneous harmonic generation and compressing of the chirped output from a femtosecond laser oscillator. In general, the aperiodic QPM gratings can be used to efficiently produce arbitrarily shaped second-harmonic pulses.

Abstract: Chemical and electrical poling is described, as well as an improved optical converter having a solid state body which employs the same.

Abstract: An apparatus and method for simultaneous chirp adjustment and frequency conversion of an ultra-short input optical pulse A.sub.1 characterized by a center angular frequency .omega..sub.1,0 in a non-linear optical material with a quasi-phasematching (QPM) grating exhibiting an aperiodic pattern of regions D.sub.j constituting a grating. Passing the ultra-short input optical pulse A.sub.1 through the grating gives rise to a chirp-adjusted and frequency-converted output optical pulse A.sub.2. In the preferred embodiment the non-linear optical material is a Second Harmonic Generator (SHG) such that the output optical pulse A.sub.2 generated from the input optical pulse A.sub.1 is a chirp-adjusted second harmonic of said ultra-short input optical pulse A.sub.1. In the general case the method and apparatus use a transfer function D(.OMEGA.) derived from the equation:A.sub.2 (.OMEGA.)=D(.OMEGA.).multidot.A.sub.1.sup.2 (.OMEGA.),where A.sub.1.sup.2 (.OMEGA.

Abstract: A method of domain patterning a body of ferroelectric material. The method includes the steps of adhering spaced conducting strips to a surface of said body; covering portions of said surface of said body between said strips with material which is insulative relative to electric current produced when an electric field configuration is created in said body and which controls the formation of fringe electric field components in said material; and applying potentials simultaneously to said conducting strips and to a surface of said insulative material to create an electric field configuration in said body whereby said strips define said electric field configuration within said body and wherein said insulating material between said strips defines a potential within said body which is generally the same as the potential applied to said conducting strips.

Abstract: Chemical and electrical poling is described, as well as an improved optical converter having a solid state body which employs the same.

Abstract: An atomic absorption apparatus using a laser for producing a light beam having a characteristic frequency f, typically ranging from several MHz to several GHz, and a characteristic polarization for measuring the absorption of that light beam by atoms of interest. The apparatus has a modulator to generate a modulating signal to modulate the characteristic frequency f and produce a phase-modulated light beam. The apparatus includes a domain where the specific atoms are located. This domain is positioned in the path of the phase-modulated light beam such that the phase-modulated light beam encounters the specific atoms when passing through the domain and some of the specific atoms absorb a portion of the phase-modulated light beam. Typically, the domains containing the atoms of interest include process chambers for vacuum coating, ion milling, sputtering, mass spectroscopy vapor coating or deposition, and the like.

Abstract: A monolithic crystalline material for quasi-phase-matching is described. The material includes a plurality of wafers of an odd multiple of coherence length thickness, having their faces bonded together by diffusion bonding. The wafers are oriented relative to one another to alternate their signs of nonlinear susceptibility. The invention also includes a method for producing optical radiation of a selected frequency by quasi-phase-matching, several specific methods and materials based on the discovery responsible for the invention, a generator for radiation of 60 THZ frequency of significant power, and a method of fabricating the material.

Abstract: A monolithic crystalline material for quasi-phase-matching is described. The material includes a plurality of wafers of an odd multiple of coherence length thickness, having their faces bonded together by diffusion bonding. The wafers are oriented relative to one another to alternate their signs of nonlinear susceptibility. The invention also includes a method for producing optical radiation of a selected frequency by quasi-phase-matching, several specific methods and materials based on the discovery responsible for the invention, a generator for radiation of 60 THZ frequency of significant power, and a method of fabricating the material.