Abstract: A glass preform is drawn into a fiber. Holes, running the length of the preform, collapse during the drawing, causing the core to have an elliptical cross section.

Abstract: PURPOSE: To form a polarization maintaining optical fiber which is long-sized and improves remarkably a polarization characteristic by forming a core of a circular or elliptical shape and forming a refractive index distribution of said core into a graded type shape.

Abstract: A glass preform (10) is drawn into a fiber. Holes (13), running the length of the preform (10), collapse during the drawing, this causes the core (11) to have an elliptical cross section.

Abstract: A radiation resistant optical waveguide fiber doped with fluorine or drawn with low tension in the fiber. The fluorine doping is substantially constant across the core and a portion of the clad adjacent the core. The concentration of the fluorine is in the range of about 0.3 to 3.0 weight percent. The draw tension is less than or equal to about 5 grams (40 dynes/cm.sup.2) to achieve optimum radiation resistance. A synergy is found when fluorine and low draw tension are applied to a fiber. Improvement in radiation resistance is largely independent of fiber type and geometry. Further improvement in radiation resistance is found when germanium is doped in a portion of the clad adjacent the core.

Abstract: A radiation resistant optical waveguide fiber doped with fluorine or drawn with low tension in the fiber. The fluorine doping is substantially constant across the core and a portion of the clad adjacent the core. The concentration of the fluorine is in the range of about 0.3 to 3.0 weight percent. The draw tension is less than or equal to about 5 grams (40 dynes/cm.sup.2) to achieve optimum radiation resistance. A synergy is found when fluorine and low draw tension are applied to a fiber. Improvement in radiation resistance is largely independent of fiber type and geometry.Further improvement in radiation resistance is found when germanium is doped in a portion of the clad adjacent the core.

Abstract: A method is disclosed for making a step-index optical fiber having a steep refractive index gradient between core and cladding. Core glass particles comprising a base glass and a refractive index-increasing dopant are deposited on a mandrel. The mandrel is removed and the resultant soot preform is consolidated to form a core preform having a dopant-poor surface region. The core glass preform is stretched and the hole therein is closed to form a core bait rod. Cladding glass soot is deposited on the core bait rod at a density which is at least 0.5 g/cc. This is accomplished by directing the flame from an auxiliary burner onto the core bait rod immediately prior to the deposition of cladding soot thereon. The resultant preform is consolidated and drawn into an optical fiber. In another embodiment, the etched core preform is overclad with a layer of cladding glass, and the composite preform is stretched prior to applying a second overclad layer.

Abstract: A dry stain for reticulocyte staining comprising a mixture of new methylene blue N dye, potassium acetate, and an anti-blood-clotting agent. The stain is prepared in a concentrated aqueous solution, filtered, dispensed volumetrically into tubes, and dried. The correct quantity of dye per tube is determined spectrophotometrically, and the proper ratio of dye to potassium acetate is determined by pH measurements. For staining reticulocytes, whole blood is added to the tube and mixed with the dry stain. Smears are then prepared on slides in a conventional manner for microscopic examination.

Abstract: A process for making BaSi.sub.2 O.sub.5 :Pb having a high energy conversion efficiency of ultraviolet emission under electron bombardment. The process includes mixing BaCO.sub.3, BaF.sub.2, Pb(NO.sub.3).sub.2 and SiO.sub.2 in a form having extremely small particle size so as to facilitate complete dispersal of the SiO.sub.2 in the mixture. Pb(NO.sub.3).sub.2, a soluble salt, is mixed with the other ingredients in a slurry of alcohol. The soluble salt dissolves in the alcohol to obtain complete dispersal of lead throughout the mixture. After mixing the other ingredients and before firing, H.sub.3 BO.sub.3 is added. The product BaSi.sub.2 O.sub.5 :Pb is used as a high efficiency phosphor in combination with photochromic glass in an information display system.