Abstract: The present invention includes an apparatus (10) and method for detecting nitrogen gas comprising: a conduit (12) for a gas sample (16); one or more hollow core photonic crystal fibers HC-PCF (20) having a proximal portion and a distal portion, wherein the proximal portion is in communication with the gas sample (16) in the conduit (12); a laser (14) positioned to strike the gas sample (16) in the conduit (12) and opposite the one or more hollow core photonic crystal fibers (20); and a Raman spectra detector (30) connected to the distal portion of the hollow core photonic crystal fibers (20), wherein a Raman spectra is generated when the laser (14) strikes the gas sample (16) that is detected by the Raman spectra detector (30).

Abstract: The invention provides methods for the use of Raman spectroscopy to non-invasively detect molecular characteristics of the constituents of the aqueous humor, vitreous humor, lens or retina. The method can be employed for the detection of molecular changes underlying ocular pathologies. In one embodiment of the invention, the method involves the steps of introducing light into the eye of the subject using a laser; collecting Raman spectra emitted from the eye; dispersing the collected Raman spectra onto a detector; and analyzing detected Raman spectral data to identify a molecular change related to an ocular pathology. The non-invasive method provided by the invention makes use of techniques and equipment that enable detection of Raman spectra with light intensities that fall within acceptable safety standards.

Abstract: A method and apparatus for evaluating optical elements which utilizes reflected images. The method allows determination of the optical effects contributed by individual surfaces of a single optical alone or in a multiple element optical system. The method is particularly useful for evaluating corneas after transplant, grafting and reshaping procedures.

Abstract: Unusual power enhancement and a plurality of output wavelengths in the visible or near-infrared regions are obtained simultaneously from a laser in which the vapors of two or more Group II-B metal halides are dissociatively excited either in an electrical discharge or by photodissociation by an external laser. By using halides involving only one metal and/or halogen isotope, the power output is greater than that obtainable with natural abundance salts. The laser output is also more confined spectrally. Over 50% of the power is contained in one or two spectrally narrow lines that are associated with a particular metal halide molecule.