Abstract: A tube fitting including a first fitting member having a cylindrical body including a flange, a second fitting member having a cylindrical body including a plurality of tines extending from the cylindrical body, the plurality of tines being configured to engage the flange where the plurality of tines and the flange are configured to secure the first and second fitting members to each other, and at least one seal disposed between the first fitting member and the second fitting member.

Abstract: A tube fitting including a first fitting member having a cylindrical body including a flange, a second fitting member having a cylindrical body including a plurality of tines extending from the cylindrical body, the plurality of tines being configured to engage the flange where the plurality of tines and the flange are configured to secure the first and second fitting members to each other, and at least one seal disposed between the first fitting member and the second fitting member.

Abstract: A spectrograph usable as a demultiplexer/detector in a wavelength division multiplexing optical system. The spectrograph comprises a planar waveguide and a detector array. The planar waveguide has a dispersive edge having an inwardly concave shape, an input edge, and a straight output edge. The dispersive edge has a reflective diffraction grating formed on it, the grating having a variable line spacing. An optical input signal comprising a plurality of different wavelength ranges enters the waveguide at the input edge, and travels through the waveguide and strikes the grating. The grating focuses the optical energy in each of the wavelength ranges at a focal spot at the output edge, the position of each focal spot being a function of wavelength. The detector array comprises a plurality of photodetectors positioned along a straight line, such that the photodetectors are positioned at the focal spots. Each photodetector therefore detects the optical energy in one of the input ranges.

Abstract: An optical source for use in an optical sensing system such as a wavelength division multiplexing system. The source produces an optical interrogation signal comprising a plurality of component signals, each component signal comprising light in a wavelength band different from the wavelength bands of the other component signals. The source comprises a concave diffraction grating, means for forming an aperture at which the interrogation signal will be formed, and a plurality of optical emitters. Each emitter is positioned such that the emitter output signal strikes the concave diffraction grating, and is focused onto the aperture, such that a portion of the emitter signal enters the aperture and forms one of the component signals. As a result, the component signal wavelengths are not sensitive to temperature-induced fluctuations in the emitter output signal.