Abstract: A multiplex coherent Raman spectrometer (10) and spectroscopy method rapidly detects and identifies individual components of a chemical mixture separated by a separation technique, such as gas chromatography. The spectrometer (10) and method accurately identify a variety of compounds because they produce the entire gas phase vibrational Raman spectrum of the unknown gas. This is accomplished by tilting a Raman cell (20) to produce a high-intensity, backward-stimulated, coherent Raman beam of 683 nm, which drives a degenerate optical parametric oscillator (28) to produce a broadband beam of 1100-1700 nm covering a range of more than 3000 wavenumber. This broadband beam is combined with a narrowband beam of 532 nm having a bandwidth of 0.003 wavenumbers and focused into a heated windowless cell (38) that receives gases separated by a gas chromatograph (40). The Raman radiation scattered from these gases is filtered and sent to a monochromator (50) with multichannel detection.

Abstract: A multiplex coherent Raman spectrometer (10) and spectroscopy method rapidly detects and identifies individual components of a chemical mixture separated by a separation technique, such as gas chromatography. The spectrometer (10) and method accurately identify a variety of compounds because they produce the entire gas phase vibrational Raman spectrum of the unknown gas. This is accomplished by tilting a Raman cell (20) to produce a high-intensity, backward-stimulated, coherent Raman beam of 683 nm, which drives a degenerate optical parametric oscillator (28) to produce a broadband beam of 1100-1700 nm covering a range of more than 3000 wavenumber. This broadband beam is combined with a narrowband beam of 532 nm having a bandwidth of 0.003 wavenumbers and focused into a heated windowless cell (38) that receives gases separated by a gas chromatograph (40). The Raman radiation scattered from these gases is filtered and sent to a monochromator (50) with multichannel detection.

Abstract: Methodology and apparatus for producing pulsed, single longitudinal mode optical energy over a widely tunable range of wavelengths by optical parametric frequency conversion.

Abstract: A laser system for producing pulsed, longitudinal mode optical energy over a widely tunable range of wavelengths. The system includes an optical cavity and a solid-state gain medium. The optical cavity comprises first, second, and third optical element means. The first optical element means reflects energy received along a first reflective optical axis and directs the energy toward the second optical element means, which diffracts the optical energy into at least two orders of interference. The energy diffracted according to a first order of interference is reflected back toward the second optical element means by a third optical element means, thereby creating a resonant optical cavity. Another portion of the optical energy diffracted by the second optical element means is produced as an output beam.

Abstract: A cavity design for use with a nonlinear medium which may be used as an oscillator using pump energy with frequency (FP) interacting with the nonlinear medium for parametrically generating outputs having a signal frequency (FS) and an idler frequency (FI) which satisfy the relationship FP=FS+FI. The cavity consists of optics and optical elements that minimize the buildup of intracavity intensity at either of the parametrically waves being generated, creating a condition in which the optical cavity is non-resonant for both the signal and idler frequencies.

Abstract: A method and apparatus for parametric conversion of electromagnetic radiation in KNbO.sub.3 crystals of optical energy at a wavelength near 1 .mu.m to optical energy at wavelengths in the range from 1.4 .mu.m to 4.6 .mu.m. A pump beam and a signal beam impinge on a KNbO.sub.3 crystal and interact to produce optical energy at an idler wavelength and a signal wavelength at the expense of optical energy of the impinging pump beam wavelength. The KNbO.sub.3 crystal has an orientation axis which is aligned with the direction of the impinging pump and signal energy and is on a locus defined by a minimum phase relation between the energy at the pump, signal, and idler frequencies.