Abstract: In one embodiment, a coupler includes a glass tube having a refractive index n3 and a passageway, a first optical waveguide and a second optical waveguide positioned within the passageway, each of the first optical waveguide and the second optical waveguide comprising a core surrounded by a cladding. The glass tube further includes a tapered region having a taper length. A coupling region is present between the first optical waveguide and the second optical waveguide within the tapered region. A refractive index of the cladding is less than a refractive index of the core, and a lowest refractive index of the cladding of the first optical waveguide and the second optical waveguide is n2. Additionally, n3 is lower than n2 such that a value of ?2-3 is 0.07%??2-3?0.125, where ?2-3 equals (n22?n32)/2n22.

Abstract: A pipe connection includes a longitudinally extending first pipe portion having an annular first flange at a first distal end of the first pipe and a longitudinally extending second pipe portion having an annular second flange at a second distal end of the second pipe. One of the flanges is a male flange and the other of the flanges is a female flange. The male flange has a ring shaped male wall longitudinally extending from a longitudinally facing flat surface of the male flange. The female flange has a ring shaped female wall longitudinally extending from a longitudinally facing first flat surface of the female flange. The male and female walls are shaped and sized such that the male wall is received within the female wall. A detent is formed from, in, and extending radially away from a first one of the walls toward a second one of the walls. A notch extends radially into the second one of the walls and is sized and shaped to receive the detent therein.