Abstract: An optogalvanic effect (OGE) detection system utilizes an intracavity sample cell and a circuit that provides low noise stable excitation and maintenance of a radio frequency (rf) driven gas discharge within the sample cell and a direct current output proportional to the if driving voltage, associated monitoring devices and software. When an optical stimulus interacts with the discharge, any electrical change in the discharge can be simply determined with high precision and accuracy by measuring the impedance of the discharge via a measurement of the direct current output. In a preferred embodiment the rf gas discharge is created with a series resonant oscillator with two push pull sections connected together to generate the high voltage signal. A current source provides a low noise stable current to power the oscillator sections. A band pass amplifier filters the current of the discharge prior to measuring it.

Abstract: An optogalvanic effect (OGE) detection system utilizes an intracavity sample cell and a circuit that provides low noise stable excitation and maintenance of a radio frequency (rf) driven gas discharge within the sample cell and a direct current output proportional to the if driving voltage, associated monitoring devices and software. When an optical stimulus interacts with the discharge, any electrical change in the discharge can be simply determined with high precision and accuracy by measuring the impedance of the discharge via a measurement of the direct current output. In a preferred embodiment the rf gas discharge is created with a series resonant oscillator with two push pull sections connected together to generate the high voltage signal. A current source provides a low noise stable current to power the oscillator sections. A band pass amplifier filters the current of the discharge prior to measuring it.

Abstract: Excimers are formed in a high pressure gas by applying a potential between a first electrode (14, 214) and a counter electrode (25, 226) so as to impose an electric field within the gas, or by introducing high energy electrons into the gas using an electron beam. A phosphor for converting the wavelength of radiation emitted from the formed excimers is disposed within the gas and outside a region (62, 162) where the excimers are expected to be formed, so as to avoid degradation of the phosphor.

Abstract: A high brightness excimer light source has an elongated tube containing an excimer-forming gas and electrodes for exciting the gas to form a plasma, and thus create excimers such as a rare gas halogen excimer or a rare gas excimer. Light emitted from the excimer propagating axially along the tube passes out of the tube through an exit device such as a lens or optical fiber at one or both ends of the tube.

Abstract: A high brightness excimer light source has an elongated tube containing an excimer-forming gas and electrodes for exciting the gas to form a plasma, and thus create excimers such as a rare gas halogen excimer or a rare gas excimer. Light emitted from the excimer propagating axially along the tube passes out of the tube through an exit device such as a lens or optical fiber at one or both ends of the tube.

Abstract: A high brightness excimer light source has an elongated tube containing an excimer-forming gas and electrodes for exciting the gas to form a plasma, and thus create excimers such as a rare gas halogen excimer or a rare gas excimer. Light emitted from the excimer propagating axially along the tube passes out of the tube through an exit device such as a lens or optical fiber at one or both ends of the tube.

Abstract: Excimers are formed in a high pressure gas by applying a potential between a first electrode (14, 214) and a counter electrode (25, 226) so as to impose an electric field within the gas, or by introducing high energy electrons into the gas using an electron beam. A phosphor for converting the wavelength of radiation emitted from the formed excimers is disposed within the gas and outside a region (62, 162) where the excimers are expected to be formed, so as to avoid degradation of the phosphor.

Abstract: A gaseous analyte including a small amount of a multiatomic moiety incorporating a particular isotope, such as 14CO2 is subjected to a standing optical wave at a resonant wavelength of the moiety while maintaining the moiety in an excited condition, such as in a gas discharge. The standing optical wave may be applied by a laser having a sample cell containing the analyte within the laser cavity. Monitoring an induced effect such as the optogalvanic effect yields a signal directly related to the quantity of the moiety. The test can detect quantities of the moiety of an attomole or less, and in some cases on the order of 100 molecules.

Abstract: A high brightness excimer light source has an elongated tube containing an excimer-forming gas and electrodes for exciting the gas to form a plasma, and thus create excimers such as a rare gas halogen excimer or a rare gas excimer. Light emitted from the excimer propagating axially along the tube passes out of the tube through an exit device such as a lens or optical fiber at one or both ends of the tube.

Abstract: A gaseous analyte including a small amount of a multiatomic moiety incorporating a particular isotope, such as 14CO2 is subjected to a standing optical wave at a resonant wavelength of the moiety while maintaining the moiety in an excited condition, such as in a gas discharge. The standing optical wave may be applied by a laser having a sample cell containing the analyte within the laser cavity. Monitoring an induced effect such as the optogalvanic effect yields a signal directly related to the quantity of the moiety. The test can detect quantities of the moiety of an attomole or less, and in some cases on the order of 100 molecules.

Abstract: Excimers are formed in a gas (30,130) by applying a pulsed potential between a first electrode (14,114) and a counter electrode (26, 126) so that corona discharge occurs, substantially without arcing, when the potential is on. The pulses or on-times of the potential desirably are about 100 microseconds or less. Use of a pulsed potential provides greater efficiency than a constant potential. Where the excimer-forming gas is a pure inert gas, the gas desirably contains less than 10 ppm water vapor.

Abstract: A method of generating light comprising the step of applying an electric field to an excimer-forming gas such as a gas mixture containing noble gases and hydrogen or halogen, and providing free electrons in the gas. The electric field is configured to accelerate electrons to at least the energy required to form excimers, but in at least one region of the electric field, the field does not substantially ionize the gas, so that the field does not induce arcing through the gas. For example, electrons can be injected from one or more field emission electrodes (18) such as one or more a metal needle tip conductors, whereas the electric field can be a field between the field emission electrodes and a counterelectrode (13).

Abstract: Excimers are generated by directing an electron beam at about 5 KeV to about 40 KeV into an excimer forming gas such as He, Ne, Ar, Kr, and Xe or mixtures of these with other gases through a ceramic foil such as SiNx. Vacuum ultraviolet (VUV) light is emitted by the excimers or by other species in contact therewith. The invention can provide intense, continuously operable broadband or monochromatic VUV light sources.

Abstract: Excimers are generated by directing an electron beam at about 5 KeV to about 40 KeV into an excimer forming gas such as He, Ne, Ar, Kr, and Xe or mixtures of these with other gases through a ceramic foil such as SiN.sub.x. Vacuum ultraviolet (VUV) light is emitted by the excimers or by other species in contact therewith. The invention can provide intense, continuously operable broadband or monochromatic VUV light sources.

Abstract: The isotopic composition of a multiatomic isotope-bearing species such as CO.sub.2 in an analyte is measured by maintaining the analyte in a condition such that isotope-bearing species are present in an excited state and directing light at wavelengths corresponding to transition energies of isotope-bearing species with different isotopes. The interaction between the analyte and light at the different wavelengths is monitored, as by monitoring the optogalvanic effect caused by the light of the different wavelengths. The light may be supplied by a laser including the isotope-bearing species. A stable isotope such as .sup.13 C or .sup.18 O can be used as a tracer in a chemical or biological test and detected using the composition-determining method.

Abstract: Analytical apparatus and methods for processing multiple samples simultaneously. Radiation such as laser light desirably including plural wavelengths is directed through multiple samples simultaneously, as by directing a beam of radiation along a single path through all of the samples. Response to each wavelength is monitored by monitoring an induced effect, other than the intensity of the applied radiation itself. Useful signal-to-noise ratios are obtained with low absorption in each sample. One sample desirably is of known composition, and serves as an internal calibration standard.

Abstract: The isotopic composition of a multiatomic isotope-bearing species such as CO.sub.2 in an analyte is measured by maintaining the analyte in a condition such that isotope-bearing species are present in an excited state and directing light at wavelengths corresponding to transition energies of isotope-bearing species with different isotopes. The interaction between the analyte and light at the different wavelengths is monitored, as by monitoring the optogalvanic effect caused by the light of the different wavelengths. The light may be supplied by a laser including the isotope-bearing species. A stable isotope such as .sup.13 C or .sup.18 O can be used as a tracer in a chemical or biological test and detected using the composition-determining method.

Abstract: A surface of a ceramic article, such as a glazed surface on a whiteware article, is treated with radiant energy such as infrared light from a laser to provide a localized remelting of the material at the surface in a fusing step. After the fusing step, the surface is treated with further radiant energy, desirably over a larger surface encompassing the fused zone and also desirably at a lower power density so as to limit the rate of cooling of the fusion zone and the immediately surrounding regions, thereby preventing thermal stress cracking. The fusion zone and surrounding regions desirably are preheated by additional radiant energy immediately prior to the fusing step so as to further limit thermal stresses during the fusing step. The process can be employed, among many other uses, for repair of glaze defects and for decoration.

Abstract: A surface of a ceramic article, such as a glazed surface on a whiteware article, is treated with radiant energy such as infrared light from a laser to provide a localized remelting of the material at the surface in a fusing step. After the fusing step, the surface is treated with further radiant energy, desirably over a larger surface encompassing the fused zone and also desirably at a lower power density so as to limit the rate of cooling of the fusion zone and the immediately surrounding regions, thereby preventing thermal stress cracking. The fusion zone and surrounding regions desirably are preheated by additional radiant energy immediately prior to the fusing step so as to further limit thermal stresses during the fusing step. The process can be employed, among many other uses, for repair of glaze defects and for decoration.

Abstract: The isotopic composition of a multiatomic isotope-bearing species such as CO.sub.2 in an analyte is measured by maintaining the analyte in a condition such that isotope-bearing species are present in an excited state and directing light at wavelengths corresponding to transition energies of isotope-bearing species with different isotopes. The interaction between the analyte and light at the different wavelengths is monitored, as by monitoring the optogalvanic effect caused by the light of the different wavelengths. The light may be supplied by a laser including the isotope-bearing species. A stable isotope such as .sup.13 C or .sup.18 O can be used as a tracer in a chemical or biological test and detected using the composition-determining method.