Abstract: Systems devices and methods in accordance with the invention impart high strength index of refraction patterns to photosensitive optical devices, such as Bragg gratings written in optical fibers. A length of small diameter fiber retaining photosensitivity is fabricated by flame elongation of an optical fiber precursor having dopant containing cladding, using a diffuse, low velocity inverted flame that does not introduce water, OH or H2 into the fiber. By varying the flame velocity during each scan the fiber is diminished to a small, uniform diameter, waist region. Photosensitivity is preserved and enhanced by exposure of the prepared waist region to scanning actinic illumination within an in-diffusing environment of pressurizing hydrogen or deuterium, and controlling the exposure to optimize the photo-induced index change.

Abstract: The present invention concerns a linear wavelength DWDM that is compact and is adapted for use with fibre ribbons and which compensates for the non-linear relationship between equally spectrally spaced wavelengths and physically spaced wavelengths once they have been diffracted. The device includes a first and second port in an optically transmissive medium. The ports are in optical communication with each other through a first and second mirror and a diffraction grating. Preferably, the first mirror is located opposite the first port, and is off-axis with respect to the optical axis. The diffraction grating is located on the same side as the input port, and is in optical communication with the first mirror. The second mirror is located on the same side as the first mirror and is in optical communication with the diffraction grating. The output port is slightly off-axis with respect to the optical axis of the second mirror and is in optical communication therewith.

Abstract: A system for evaluating a donor cornea includes a light source for generating a beam having a predetermined characteristic and a selected configuration. The light beam characteristic can be collimated light (wavefront analysis), white light (spectral analysis), or polarized light (polarization analysis). The beam configuration can be either circular in cross-section, or it can be a slit. When circular, the light beam is transmitted through the entire cornea to identify changes in the characteristics of the light (e.g. phase shift, spectral shift, or polarization changes). These changes then determine the optical properties of the donor cornea. When configured as a slit, the light is scattered off-axis and used to measure dimensions for a profile of the donor cornea. A computer then prepares an evaluation which includes information on both the optical qualities and the dimensional profile of the donor specimen.

Abstract: The present invention relates to an amplification optical fiber comprising a structure which can yield a higher amplification gain, and a fiber optic amplifier including the same. The fiber optic amplifier comprises, at least, an amplification optical fiber for amplifying signals having wavelengths different from each other, and a pumping light source for supplying pumping light for signal amplification. The amplification optical fiber has one end for inputting pumping light and has a cutoff wavelength shorter than the signal wavelength but longer than the pumping light wavelength.