Abstract: A method is disclosed for sorting textiles, as is a system that operates in accordance with the method. The method includes steps of (a) providing a plurality of textiles to be sorted, each of the textiles comprising a portion that includes an electromagnetic radiation emitting and amplifying material; for each textile, (b) illuminating at least the portion with laser light that exceeds a threshold fluence; (c) detecting a narrow band laser-like emission of at least one wavelength from the portion in response to the step of illuminating; and (d) sorting the textiles based on the detected laser-like emission. In one embodiment the textile has at least one stitched-in thread, the thread comprising a substrate material and the electromagnetic radiation emitting and amplifying material in combination with scatterers for providing the laser-like emission. In another embodiment the textile has an applied patch containing the electromagnetic radiation emitting and amplifying material.

Abstract: A class of high efficiency (e.g., .gtoreq.20%) materials for use as display pixels to replace conventional phosphors in television, monitor, and flat panel displays. The materials are comprised of nanocrystals such as CdS.sub.x Se.sub.1-x, CuCl, GaN, CdTe.sub.x S.sub.1-x, ZnTe, ZnSe, ZnS, or porous Si or Ge alloys which may or may not contain a luminescent center. The nanocrystals may be doped with a luminescent center such as Mn.sup.2+ or a transition metal. The nanocrystals have passivated surfaces to provide high quantum efficiency. The nanocrystals have all dimensions comparable to the exciton radius (e.g., a size in the range of approximately 1 nm to approximately 10 nm). A quantum dot nanocrystal display phosphor that has a size selected for shifting an emission wavelength of a constituent semiconductor material from a characteristic wavelength observed in the bulk to a different wavelength.

Abstract: A structure generates electromagnetic radiation having at least one wavelength selected for activating a photo-sensitive substance that is applied to a tissue to be treated. The structure is particularly useful for photo-dynamic therapy (PDT) applications. The structure includes a body of material, such as a polymer filament, band, or substrate, that contains a gain medium. The gain medium in turn contains a substance (such as dye molecules) for generating a stimulated emission that includes the at least one wavelength when excited by a pump wavelength, and a plurality of scattering sites (such as scattering particles) for scattering the stimulated emission to provide a narrow band emission at the at least one selected wavelength. The narrow band emission in turn activates the photo-sensitive therapeutic substance.

Abstract: An optical source (10) for exciting a photosensitive drug that responds to light within a predetermined band of wavelengths. The optical source uses a chemiluminescent source in combination with at least one fluorescer selected to output light within the predetermined band of wavelengths. The chemiluminescent source can be flowed during use. In one embodiment the chemiluminescent source is stored in a heated reservoir, and is pumped from the reservoir through a conduit, such as a catheter. A patch can be used for spreading the chemiluminescent source over a wider area. An active feedback system can also be used for controlling the output light. In preferred embodiments a plurality of reactants are mixed for forming a chemiluminescent source in combination with at least one fluorescer selected to output light within the predetermined band of wavelengths.

Abstract: A gain medium is comprised of a multi-phase system wherein: a first phase is an electromagnetic radiation emission phase; a second phase is an electromagnetic radiation scattering phase; and a third phase is a transparent matrix phase. By example, the emission phase may consist of dye molecules, the scattering phase may consist of high contrast particles, and the matrix phase may consist of a solvent such as methanol. In some embodiments of this invention the emission and scattering phases may be the same phase, as when semiconductor particles are employed. A smallest dimension of a body comprised of the gain medium may be less than a scattering length associated with the scattering phase. It is shown that nearly thresholdless laser behavior is observed in strongly scattering optically pumped dye-methanol solutions containing colloidal TiO.sub.2 or Al.sub.2 O.sub.3 ruby nanoparticles.

Abstract: Disclosed is a method for activating photosensitive therapeutic and other compounds, comprising the steps of (a) providing a photosensitive therapeutic compound in combination with an appropriate solvent, such as dimethyl phthalate (DMP); (b) generating acoustic energy for generating free radicals from the solvent and reacting the free radicals with an oxalate ester to generate a key intermediate; (c) transferring chemical energy to the photosensitive therapeutic compound from the key intermediate; and (d) activating the photosensitive compound with the transferred energy. In an illustrative embodiment of this invention the oxalate ester is comprised of ester bis (2,4-dinitrophenyl) oxalate (DNPO). Also disclosed is a method for enhancing the effectiveness of photodynamic therapy by also generating acoustic energy to increase selectivity and/or increase the numbers of free radicals.

Abstract: This invention teaches an optical source (10) for performing photomedicine. The optical source includes a Nd:YLF laser (12) having an output providing light having a wavelength of 1.053 micrometers; a frequency doubler (13) that is optically coupled to the laser output for converting a portion of the light to frequency doubled light, the frequency doubler having an output providing frequency doubled light having a wavelength of 526.5 nm; and, coupled to the output of the frequency doubler, a unit (14) for shifting the frequency doubled light to light having a wavelength of about 630 nm. In a presently preferred embodiment of this invention the shifting unit includes a device for performing stimulated Raman scattering of the frequency doubled light for creating the third Stokes line at 630.1 nm. The device includes a crystal comprised of a R.sub.x (MO.sub.3).sub.y compound and means for establishing a multi-pass or resonant cavity optical configuration through the crystal.

Abstract: This invention teaches a method for fabricating a microlens within a window of a laser diode assembly, and a laser diode assembly fabricated in accordance with the method. The method includes the steps of (a) providing a laser diode assembly that includes a window that is substantially transparent at wavelengths emitted by a laser diode within the assembly, the window comprising a wavelength-selective absorber of electromagnetic radiation; and (b) irradiating a portion of a surface of the window with electromagnetic radiation having wavelengths within a range of wavelengths that are absorbed by the wavelength selective absorber such that a portion of the electromagnetic radiation is absorbed for heating and melting the material adjacent to the surface region, whereby the melted material rises up above the surface to form, when re-solidified, the microlens.

Abstract: Disclosed is a method of preparing refractive microlenses in a single step, utilizing laser-induced surface structure formation in semiconductor doped glasses (SDGs). The SDG materials, in conjunction with above-bandgap wavelength laser sources, are used to fabricate lenses that operate with light of below-bandgap wavelengths. In accordance with the teaching of this invention lenses on an approximately 5-500 .mu.m diameter scale are fabricated individually or in arrays by laser irradiation of absorbing glasses. The microlenses have controllable characteristics and can be fabricated to have focal lengths as short as tens of microns. The lenses are generally parabolic or spherical in shape and are highly reproducible.

Abstract: An optical element includes a phase mask made of a nonlinear material. The element uses the nonlinearity to produce an intensity dependent lens which controls the imaging properties. The invention enables the optical control of the image of an array produced by a diffractive spot generator in direct contact with a thin semiconductor doped glass substrate. By example, the focus of an image at 632.8 nm from a He-Ne laser is controlled by 514.5 nm light from an Argon Ion laser.

Abstract: A method is disclosed for identifying an object. The method includes the steps of (a) providing individual ones of objects within a predetermined class of objects with a gain medium comprised of an electromagnetic radiation emitting and amplifying first phase and an electromagnetic radiation scattering second phase, the gain medium being responsive to electromagnetic radiation having a first wavelength for emitting electromagnetic radiation with wavelengths within a predetermined band of wavelengths; (b) irradiating the objects with the first wavelength; (c) detecting an emission from the irradiated objects, the emission including one or more second wavelengths that are within the predetermined band of wavelengths; and (d) identifying an object as belonging to a predetermined class of objects from the detected emission. Also disclosed is a method for detecting the presence of a structure within an object, which also employs the gain medium and the step of irradiating.

Abstract: Disclosed is a method of preparing refractive microlenses in a single step, utilizing laser-induced surface structure formation in semiconductor doped glasses (SDGs). The SDG materials, in conjunction with above-bandgap wavelength laser sources, are used to fabricate lenses that operate with light of below-bandgap wavelengths. In accordance with the teaching of this invention lenses on an approximately 5-500 .mu.m diameter scale are fabricated individually or in arrays by laser irradiation of absorbing glasses. The microlenses have controllable characteristics and can be fabricated to have focal lengths as short as tens of microns. The lenses are generally parabolic or spherical in shape and are highly reproducible.

Abstract: There is described a semiconductor microcrystallite doped glass that exhibits SHG, and a method of preparing, or encoding, a semiconductor microcrystallite doped glass by the simultaneous injection of fundamental and second harmonic fields, such as 1.06 .mu.m and 532 nm. More specifically, the disclosure pertains to a structure that exhibits SHG, the structure being comprised of, by example, borosilicate glass that contains CdS.sub.x Se.sub.1-x microcrystallites. Also disclosed are embodiments of devices having an optical waveguide structure formed within a glass substrate that contains semiconductor microcrystallites. The optical waveguide structure guides and contains injected radiation and also converts a portion thereof to the second harmonic. Also disclosed are optoelectronic devices that include frequency doublers, self-doubling lasant material, bichromatic optical switches, and a volume holographic medium, all of which include a glass host having semiconductor microcrystallites embedded within.

Abstract: Multiple bits of information are stored in the frequency domain in a bulk glass using optically encoded .chi..sup.(2) gratings. The information is read out by measuring a second harmonic generation (SHG) from the encoded glass as a function of wavelength. Information storage densities in excess of 10.sup.8 bits/cm.sup.2 are readily achievable. The stored information is stable under readout conditions, and the information can be erased and rewritten.

Abstract: There is described a semiconductor microcrystallite doped glass that exhibits SHG, and a method of preparing, or encoding, a semiconductor microcrystallite doped glass by the simultaneous injection of fundamental and second harmonic fields, such as 1.06 .mu.m and 532 nm. More specifically, the disclosure pertains to a structure that exhibits SHG, the structure being comprised of, by example, borosilicate glass that contains CdS.sub.x Se.sub.1-x microcrystallites. Also disclosed are embodiments of devices having an optical waveguide structure formed within a glass substrate that contains semiconductor microcrystallites. The optical waveguide structure guides and contains injected radiation and also converts a portion thereof to the second harmonic. Also disclosed are optoelectronic devices that include frequency doublers, self-doubling lasant material, bichromatic optical switches, and a volume holographic medium, all of which include a glass host having semiconductor microcrystallites embedded within.

Abstract: A method for preparing a material so as to exhibit second harmonic generation for optical radiation that passes through the material. The method includes a first step of providing a bulk glass comprised of substitutionally doped silica and a charge transfer dopant. The bulk glass is prepared for frequency doubling in accordance with a method that includes a step of irradiating the bulk glass with optical radiation having a first wavelength and a second wavelength, the bulk glass being irradiated for a period of time sufficient to obtain a desired amount of conversion efficiency of the first wavelength into the second wavelength. The silica is substitutionally doped with an element selected from the group consisting of Ge and Al, and the charge transfer dopant is selected from the group consisting of Ce.sup.3+, Nd.sup.3+, and Eu.sup.2+. In another embodiment of the invention the silica is substitutionally doped with Ge and the charge transfer dopant is comprised of naturally existing Ge defects.

Abstract: A gain medium is comprised of a multi-phase system wherein: a first phase is an electromagnetic radiation emission phase; a second phase is an electromagnetic radiation scattering phase; and a third phase is a transparent matrix phase. By example, the emission phase may consist of dye molecules, the scattering phase may consist of high contrast particles, and the matrix phase may consist of a solvent such as methanol. In some embodiments of this invention the emission and scattering phases may be the same phase, as when semiconductor particles are employed. A smallest dimension of a body comprised of the gain medium may be less than a scattering length associated with the scattering phase. It is shown that nearly thresholdless laser behavior is observed in strongly scattering optically pumped dye-methanol solutions containing colloidal TiO.sub.2 or Al.sub.2 O.sub.3 ruby nanoparticles.

Abstract: There is described a semiconductor microcrystallite doped glass that exhibits SHG, and a method of preparing, or encoding, a semiconductor microcrystallite doped glass by the simultaneous injection of fundamental and second harmonic fields, such as 1.06 .mu.m and 532 nm. More specifically, the disclosure pertains to a structure that exhibits SHG, the structure being comprised of, by example, borosilicate glass that contains CdS.sub.x Se.sub.1-x microcrystallites. Also disclosed are embodiments of devices having an optical waveguide structure formed within a glass substrate that contains semiconductor microcrystallites. The optical waveguide structure guides and contains injected radiation and also converts a portion thereof to the second harmonic. Also disclosed are optoelectronic devices that include frequency doublers, self-doubling lasant material, bichromatic optical switches, and a volume holographic medium, all of which include a glass host having semiconductor microcrystallites embedded within.

Abstract: There is described a semiconductor microcrystallite doped glass that exhibits SHG, and a method of preparing, or encoding, a semiconductor microcrystallite doped glass by the simultaneous injection of fundamental and second harmonic fields, such as 1.06 .mu.m and 532 nm. More specifically, the disclosure pertains to a structure that exhibits SHG, the structure being comprised of, by example, borosilicate glass that contains CdS.sub.x Se.sub.1-x microcrystallites. Also disclosed are embodiments of devices having an optical waveguide structure formed within a glass substrate that contains semiconductor microcrystallites. The optical waveguide structure guides and contains injected radiation and also converts a portion thereof to the second harmonic. Also disclosed are optoelectronic devices that include frequency doublers, self-doubling lasant material, bichromatic optical switches, and a volume holographic medium, all of which include a glass host having semiconductor microcrystallites embedded within.

Abstract: A method for preparing a material so as to exhibit second harmonic generation for optical radiation that passes through the material. The method includes a first step of providing a bulk glass comprised of substitutionally doped silica and a charge transfer dopant. The bulk glass is prepared for frequency doubling in accordance with a method that includes a step of irradiating the bulk glass with optical radiation having a first wavelength and a second wavelength, the bulk glass being irradiated for a period of time sufficient to obtain a desired amount of conversion efficiency of the first wavelength into the second wavelength. The silica is substitutionally doped with an element selected from the group consisting of Ge and Al, and the charge transfer dopant is selected from the group consisting of Ce.sup.3+, Nd.sup.3+, and Eu.sup.2+. In another embodiment of the invention the silica is substitutionally doped with Ge and the charge transfer dopant is comprised of naturally existing Ge defects.