An amplification fiber which can generate a laser beam in a visible region even when a silica glass is used as a base material of a core of the amplification fiber is realized. An amplification fiber according to an embodiment of the present disclosure includes a core configured to generate a laser beam from an excitation beam in a visible region, and a cladding surrounding the core. The core is composed of a core material including Dy, one or more elements selected from Al, Ge, and P, and a silica glass.

An optical fiber can include a core comprising silica co-doped with nitrogen and chlorine and an outer cladding surrounding the core. In some aspects, the core can be characterized by an annealing temperature of less than or equal to about 1150° C. and/or the core can include a relative refractive index Δ.sub.core in a range of from about 0.15% to about 0.45%.

An aluminoborosilicate glass includes alkaline earth oxides and is substantially free of alkali oxides. The glass may be fusion formable and may be useful as a substrate or other article, such as with consumer and commercial electronic devices.

An aluminoborosilicate glass includes alkaline earth oxides and is substantially free of alkali oxides. The glass may be fusion formable and may be useful as a substrate or other article, such as with consumer and commercial electronic devices.

A photodarkening-resistant ytterbium-doped quartz optical fiber and a method for prpearing such a fiber are provided. Glass of a photodarkening-resistant ytterbium-doped quartz optical fiber core rod includes at least Yb.sub.2O.sub.3, Al.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2. The proportions of Yb.sub.2O.sub.3, Al.sub.2O.sub.3, and P.sub.2O.sub.5 in the entire substance are Yb.sub.2O.sub.3: 0.05-0.3 mol %, Al.sub.2O.sub.3: 1-3 mol %, and P.sub.2O.sub.5: 1-5 mol %, respectively. In the preparation method for the photodarkening-resistant ytterbium-doped quartz optical fiber, a sol-gel method and an improved chemical vapor deposition method are combined. By using the molecular-level doping uniformity and the low preparation loss thereof respectively, ytterbium ions, aluminum ions and phosphorus ions are effectively doped in a quartz matrix, thereby effectively solving the problems in the optical fiber of high loss, photodarkening caused by cluster or the like, and a central refractive index dip.

Alkali-doped boroaluminosilicate glasses are provided. The glasses include the network formers SiO.sub.2, B.sub.2O.sub.3, and Al.sub.2O.sub.3. The glass may, in some embodiments, have a Young's modulus of less than about 65 GPa and/or a coefficient of thermal expansion of less than about 40×10.sup.−7/° C. The glass may be used as a cover glass for electronic devices, a color filter substrate, a thin film transistor substrate, or an outer clad layer for a glass laminate.

A fiber optic imaging element includes medium-expansion and a fabrication method including: (1) matching a core glass rod with a cladding glass tube to perform mono fiber drawing; (2) arranging the mono fibers into a mono fiber bundle rod, and then drawing the mono fiber bundle rod into a multi fiber; (3) arranging the multi fiber into a multi fiber bundle rod, and then drawing the multi fiber bundle rod into a multi-multi fiber; (4) cutting the multi-multi fiber, and then arranging the multi-multi fiber into a fiber assembly buddle, then putting the fiber assembly buddle into a mold of heat press fusion process, and performing the heat press fusion process to prepare a block of the fiber optic imaging element with medium-expansion; and (5) edged rounding, cutting and slicing, face grinding and polishing the prepared medium-expansion block into a billet.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein Th is at least about 50° C., preferably 50° C.<Th.sub.h<250° C.

A composition for producing a glass fiber, including the following components with corresponding percentage amounts by weight: SiO.sub.2: 57.4-60.9%; Al.sub.2O.sub.3: greater than 17% and less than or equal to 19.8%; MgO: greater than 9% and less than or equal to 12.8%; CaO: 6.4-11.8%; SrO: 0.1-1.5%; Na.sub.2O+K.sub.2O: 0.1-1.1%; Fe.sub.2O.sub.3: 0.05-1%; TiO.sub.2: lower than 0.8%; and SiO.sub.2+Al.sub.2O.sub.3: lower than or equal to 79.4%. The total weight percentage of the above components in the composition is greater than 99%. The weight percentage ratio of Al.sub.2O.sub.3+MgO to SiO.sub.2 is between 0.43 and 0.56, and the weight percentage ratio of CaO+MgO to SiO.sub.2+Al.sub.2O.sub.3 is greater than 0.205. The composition can significantly increase the glass modulus, effectively reduce the glass crystallization rate, secure a desirable temperature range (ΔT) for fiber formation and enhance the refinement of molten glass, thus making it particularly suitable for high performance glass fiber production with refractory-lined furnaces.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50° C., preferably 50° C.<T.sub.h<250° C.