Technologies for a strong rare-earth-ion interactions are disclosed. In the illustrative embodiment, a heterogeneous slot waveguide is formed with two layers of silicon surrounding a layer of Er:Y2O3, resulting in a waveguide that supports a TM mode with a strong confinement of electromagnetic field near the erbium dopants. The strong concentration of electromagnetic field and small mode volume allows for strong interactions between optical fields and the erbium dopants. In some embodiments, the slot waveguide structure may be configured as a microring resonator or a photonic crystal, resulting in small-mode-volume resonators with high Q-factors. In some embodiments, strong electro-optic and/or acousto-optic coupling may be achieved, resulting in quantum transducer able to coherently convert between signals in different systems.

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.

The invention relates to a method for depositing metal particles on a textile support, which comprises: placing at least one textile sheet (1) made of side-emitting optical fibers (2) in contact with a solution containing at least one ionic precursor of a metal to be deposited, the textile sheet (1) being formed from optical fibers (2) woven in warp and/or weft with binding threads in warp and/or weft, each of the optical fibers (2) having invasive alterations (5) along the fiber and allowing the emission of light propagating in the fiber at these alterations (5), the textile sheet (1) being coated on all or part of the surfaces thereof with a layer of semiconductor particles (4) having photocatalytic properties, the textile sheet (1) and the solution being contained in a space of a reactor (9), the space being free of oxygen; illuminating the textile sheet (1) by at least one light source (7) connected to all or part of the free ends (6) of the optical fibers (2), the light source generating light radiation suitable for activating the photocatalysis of the semiconductor inducing the deposition of metal particles on the photocatalytic layer (4).

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.

A photodarkening-resistant ytterbium-doped quartz optical fiber and a method for preparing 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.

The invention relates to an optical fiber preform (20) comprising a primary preform (21) and one or more purified silica-based overclad layers (22) surrounding said primary preform (21), the purified silica-based overclad layers (22) comprising lithium and aluminium, and having a ratio between lithium concentration [Li] and aluminium concentration [Al] satisfying the following inequality:
1×10.sup.−3≤[Li]/[Al]≤20×10.sup.−3.

An optical fiber and a method of fabrication thereof. The optical fiber includes a core; a cladding surrounding the core; a primary metal coating surrounding the cladding and including a noble metal having a melting point of at least 500 degrees Celsius; and a secondary metal coating surrounding the primary coating and having a melting point higher than the melting point of the primary metal coating, a thickness of the primary metal coating being greater than a thickness of the secondary metal coating.

An optical fiber and a method of fabrication thereof. The optical fiber includes a core; a cladding surrounding the core; a primary metal coating surrounding the cladding and including a noble metal having a melting point of at least 500 degrees Celsius; and a secondary metal coating surrounding the primary coating and having a melting point higher than the melting point of the primary metal coating, a thickness of the primary metal coating being greater than a thickness of the secondary metal coating,

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.

The systems and methods of forming optical fiber coatings with reduced defects include moving a bare optical fiber through first and second coating sub-systems. The first coating sub-system forms a first coating on the bare optical fiber by depositing a first coating material and then curing the deposited first coating material with actinic light. This process also results in the formation of stray actinic light. The process also includes moving the coated optical fiber through a second coating sub-system to form a second coating on the first coating. A light-blocking device resides between the first and second coating sub-systems to block the stray actinic light. Without the light-blocking device, the stray actinic light can enter the second coating sub-system and reach the second coating material therein and form a gel therefrom, which in turn leads to defects in the coated optical fiber exiting the second coating sub-system.