Submerged combustion systems and methods of use to produce foamed glass. One system includes a submerged combustion melter having an outlet, the melter configured to produce an initial foamy molten glass having a density and comprising bubbles filled primarily with combustion product gases. The initial foamy molten glass is deposited directly onto or into a transport apparatus that transports the initial foamy molten glass to a downstream processing apparatus. An intermediate stage may be included between the melter and the transport apparatus. One intermediate stage is a channel that includes gas injectors. Another intermediate stage is a channel that produces an upper flow of a less dense glass and a relatively more dense glass lower flow. The upper flow may be processed into foamed glass products, while the more dense flow may be processed into dense glass products.

Provided is a method for manufacturing bent optical fibers with which bent optical fibers having a quality difference effectively reduced can be manufactured without a reduction of the manufacturing yield. In the present embodiment, an elastic bending process and a heating process are alternately repeated. In the elastic bending process, a movement restricting member rotatable around a revolving shaft is rotated while an optical fiber having its leading end portion held by the movement restricting member is fed toward the revolving shaft to form bent portions at a part of the optical fiber. In the heating process, the optical fiber is irradiated with a laser beam to relieve stress at the bent portions. Thus, multiple bent portions at which the stress is relieved are formed in the optical fiber along the longitudinal direction of the optical fiber.

Provided is a method for manufacturing bent optical fibers with which bent optical fibers having a quality difference effectively reduced can be manufactured without a reduction of the manufacturing yield. In the present embodiment, an elastic bending process and a heating process are alternately repeated. In the elastic bending process, a movement restricting member rotatable around a revolving shaft is rotated while an optical fiber having its leading end portion held by the movement restricting member is fed toward the revolving shaft to form bent portions at a part of the optical fiber. In the heating process, the optical fiber is irradiated with a laser beam to relieve stress at the bent portions. Thus, multiple bent portions at which the stress is relieved are formed in the optical fiber along the longitudinal direction of the optical fiber.

Surface-modified glass fiber, comprising: a core made of a first glass fiber material; a surface layer that encloses the core completely in a sheath-like way; wherein the surface layer has a higher silicon dioxide percentage and a higher porosity compared to the core.

Surface-modified glass fiber, comprising: a core made of a first glass fiber material; a surface layer that encloses the core completely in a sheath-like way; wherein the surface layer has a higher silicon dioxide percentage and a higher porosity compared to the core.

An optical fiber for efficient coupling of optical signals to photonic devices. The optical fiber includes a Cl doped tapered core region with a changing outer diameter and changing maximum core refractive index to provide improved coupling at wavelength of interest to photonic devices. The photonic devices may be, for example, silicon photonic devices with an operating wavelength at or near 1310 nm, or at or near 1550 nm.

An optical fiber for efficient coupling of optical signals to photonic devices. The optical fiber includes a Cl doped tapered core region with a changing outer diameter and changing maximum core refractive index to provide improved coupling at wavelength of interest to photonic devices. The photonic devices may be, for example, silicon photonic devices with an operating wavelength at or near 1310 nm, or at or near 1550 nm.

Embodiments of the present invention pertain to glass compositions, glasses and articles. The articles include an aluminosilicate glass, which may include P.sub.2O.sub.5 and K.sub.2O.

Embodiments of the present invention pertain to glass compositions, glasses and articles. The articles include an aluminosilicate glass, which may include P.sub.2O.sub.5 and K.sub.2O.

A submerged combustion melter 10 is arranged with a vertical melting chamber 11, which may be cylindrical, and at least five submerged combustion burners 21-26 in the bottom base 13, the burners so spaced apart from each other and from the walls and angled from the vertical that in use a toroidal flow pattern can be achieved, providing intensive mixing. The claims also pertain to a method of melting a vitrifiable material from solid batch by submerged combustion melting.