Abstract: A small, handheld Raman spectrometer device can be built from a laser, lenses, and a diffraction grating configured in a right-angle Raman spectroscopy geometry, and used in conjunction with a cell-phone camera to record the Raman spectra. The cell-phone-based Raman spectrometer system is suited to performing in-situ measurements of chemical and biological molecules.

Abstract: A small, handheld Raman spectrometer device can be built from a laser, lenses, and a diffraction grating configured in a right-angle Raman spectroscopy geometry, and used in conjunction with a cell-phone camera to record the Raman spectra. The cell-phone-based Raman spectrometer system is suited to performing in-situ measurements of chemical and biological molecules.

Abstract: A hand-held synchronous scan spectrometer for in situ analysis of bacteria, viruses, and fungi includes a housing that contains a light source, a first monochromator positioned to receive light from the light source and operable to direct a wavelength of the light from the light source towards a sample, a second monochromator positioned to receive fluoresced light from the sample and light from first monochromator, and a detector disposed within the housing and positioned to receive light output from the second monochromator. The hand-held synchronous scan spectrometer can include a display that is integrated into the housing or can utilize a display of a removable display device (e.g., a cell phone, PDA, tablet, and the like).

Abstract: A hand-held synchronous scan spectrometer for in situ analysis of bacteria, viruses, and fungi includes a housing that contains a light source, a first monochromator positioned to receive light from the light source and operable to direct a wavelength of the light from the light source towards a sample, a second monochromator positioned to receive fluoresced light from the sample and light from first monochromator, and a detector disposed within the housing and positioned to receive light output from the second monochromator. The hand-held synchronous scan spectrometer can include a display that is integrated into the housing or can utilize a display of a removable display device (e.g., a cell phone, PDA, tablet, and the like).

Abstract: Photochromic chemicals consisting essentially of colored fluorescent heterocyclic fulgides are particularly suitable for optical memories. The preferred heterocyclic photochromic fulgides consist essentially of colored 2-indolyfulgides capable of excitation by ultraviolet light to fluoresce. These heterocyclic photochromic fulgides are preferably synthesized by process of (1) condensation of 1,3-dimethyl-(5-substituted)indole-2-carboxaldehyde with diethyl IV iospropylidenesuccinate as a key intermediate; followed by (2) hydrolysis; and (3) intramolecular acid anhydride formation.

Abstract: Selected domains, normally 2×103×2×103 such domains arrayed in a plane, within a three-dimensional (3-D) volume of radiation-sensitive medium, typically 1 cm3 of spirobenzopyran containing 2×103 such planes, are temporally and spatially simultaneously illuminated by two radiation pulses, normally laser light pulses in various combinations of wavelengths 532 nm and 1024 nm, in order, dependent upon the particular combination of illuminating light, to either write binary data to, or read binary data from, the selected domains by process of two-photon (2-P) interaction/absorption. One laser light pulse is preferably directed to illuminate all domains during its propagation along one directional axis of the volume. The other laser light pulse is first spatially encoded with binary information by 2-D spatial light modulator, and is then (i) directed and (ii) time sequenced to intersection with the other light pulse in a locus of intersection domains.

Abstract: Dye precursor molecules—normally rhodamine base—held in a transparent matrix are reactive with acids, bases, ions or radicals—and in the case of rhodamine are reactive with acids—to produce dye molecules—i.e., rhodamine—having markedly different spectroscopic properties. Light-sensitive molecules—normally a compound of ortho-nitro-aldehyde, in particular o-nitro-benzaldehyde or, preferably, 1-nitro-2-naphthaldehyde—in the same matrix undergo photochemical reaction when selectively exposed to light so as to form at least one of the acids, bases, ions or radicals with which the dye precursor molecules are reactive—preferably nitroso acid.

Abstract: Three-, and four-dimensional (“3-D” and “4-D”) volume radiation memories store multiple binary bits of information—typically about five to ten and more typically eight such bits—in the same physical volumes on several different photochromic chemicals co-located in the volume. Each of the multiple photochromic chemicals is individually selectively written with an individually associated pair of radiation beams of an appropriate combined frequency—i.e., a “color”—and energy by a process of two-photon (“2-P”) absorption. All the multiple information bits that are stored within all the photochromic chemicals in each addressable domain are read in common, and induced to simultaneously fluoresce, again by process of 2-P absorption.

Abstract: Dye precursor molecules—normally rhodamine base—held in a transparent matrix are reactive with acids, bases, ions or radicals—and in the case of rhodamine are reactive with acids—to produce dye molecules—i.e., rhodamine—having markedly different spectroscopic properties. Light-sensitive molecules-normally a compound of ortho-nitro-aldehyde, in particular o-nitro-benzaldehyde or, preferably, 1-nitro-2-naphthaldehyde—in the same matrix undergo photochemical reaction when selectively exposed to light so as to form at least one of the acids, bases, ions or radicals with which the dye precursor molecules are reactive—preferably nitroso acid.

Abstract: A photoemissive photocathode, being a metal with a low work function and preferably tantalum-surfaced cesium-antimonide, is illuminated with pulses of 5320 .ANG. laser light, typically 20 psec at a 20 Hz repetition rate, to emit electrons by the photoelectric effect. The emitted electrons are accumulated in a spatial region near the photocathode by a grid electrode. The same laser pulses activate a semiconductor switch, normally an LiTaO.sub.3 crystal doped with 2.24% Cu, to apply a high voltage, typically 100 Kv, between the photocathode and an anode. The accumulated electrons are accelerated, and focused, as an electron beam that strikes the anode, typically in a focal spot of less than 0.5 mm diameter. Time-resolved x-ray pulses, typically K band of 20 picoseconds duration with 4-10 microjoules energy each, are produced. A laser-induced pulsed wide-area table-top-size embodiment of the x-ray source reliably generates a 1-10 mW/cm.sup.2 flux of hard, 0.

Abstract: A photoemissive photocathode, being a metal with a low work function and preferably tantalum-surfaced cesium-antimonide, is illuminated with pulses of 5320 .ANG. laser light, typically 20 psec at a 20 Hz repetition rate, to emit electrons by the photoelectric effect. The emitted electrons are accumulated in a spatial region near the photocathode by a grid electrode. The same laser pulses activate a semiconductor switch, normally an LiTaO.sub.3 crystal doped with 2.24% Cu, to apply a high voltage, typically 100 Kv, between the photocathode and an anode. The accumulated electrons are accelerated, and focused, as an electron beam that strikes the anode, typically in a focal spot of less than 0.5 mm diameter. Time-resolved x-ray pulses, typically K band of 20 picoseconds duration with 4-10 microjoules energy each, are produced. A laser-induced pulsed wide-area table-top-size embodiment of the x-ray source reliably generates a 1-10 mW/cm.sup.2 flux of hard, 0.

Abstract: Selected domains, normally 10.sup.3 .times.10.sup.3 such domains arrayed in a plane, within a three-dimensional (3-D) volume of active medium, typically 1 cm.sup.3 of spirobenzopyran containing 10.sup.2 such planes, are temporally and spatially simultaneously illuminated by two radiation beams, normally laser light beams in various combinations of wavelengths 532nm and 1024nm, in order, dependent upon the particular combination of illuminating light, to either write binary data to, or read binary data from, the selected domains by process of two-photon (2-P) absorption. One laser light beam is preferably directed to illuminate all domains of the selected plane in and by a one-dimensional spatial light modular (1-D SLM). The other laser light beam is first spatially encoded with binary information by 2-D SLM, and is then also directed to illuminate the domains of the selected plane.

Abstract: An active medium, typically a photochromic material and more typically spirbenzopyran, maintained in a three-dimensional matrix, typically of polymer, is illuminated in selected regions by two UV laser light beams, typically of 532 nm. and 1064 nm. wavelength, to change from a first, spiropyran, to a second, merocyanine, stable molecular isomeric form by process of two-photon absorption. Regions not temporally and spatially coincidently illuminated are unchanged. Later illumination of the selected regions by two green-red laser light beams, typically of 1064 nm wavelength each, causes only the second, merocyanine, isomeric form to fluoresce. This fluorescence is detectable by photodetectors as stored binary data. The three-dimensional memory may be erased by heat, or by infrared radiation, typically 2.12 microns wavelength. Use of other medium permit the three-dimensional patterning of three-dimensional forms, such as polystyrene polymer solids patterned from liquid styrene monomer.

Abstract: A photoemissive photocathode, preferably tantalum-surfaced cesium-antimonide, is illuminated with pulses of 5320 .ANG. laser light, typically 20 psec. at an 20 Hz repetition rate, to emit electrons by the photoelectric effect. The emitted electrons are accumulated in a spatial region near the photocathode by a grid electrode. The same laser pulses activate a semiconductor switch, normally an LiTaO.sub.3 crystal doped with 2.24% Cu, to apply a high voltage, typically 100 kV, between the photocathode and an anode. The accumulated electrons are accelerated, and focused, as an electron beam that strikes the anode, typically in a focal spot of less than 0.5 mm diameter. Time-resolved x-ray pulses, typically K band of 20 picoseconds duration with 4-10 microjoules energy each, are produced. The x-ray pulses are useable in x-ray lithography, or in x-ray spectroscopy of a specimen in which molecular reaction is initiated and/or energized by the same laser light pulses that also give rise to the x-ray pulses.

Abstract: A class of elements is dependent upon induced absorption for transmitted energy. Absorption is introduced by first pumping an active medium to produce a first excited state--generally an electronically excited state--whereafter the energy level of such excited state is reduced to a lower "metastable" excited state or by pumping directly to such metastable state. Increased absorption for radiation of a quantum energy corresponding with the difference between the metastable and some higher excited state occurs during the time interval that population of the metastable state is maintained. Elements may operate as extremely rapid shutters, switches, modulators, pulse sharpeners, etc.