36 results about "Photodarkening" patented technology

A light-emitting device is provided which includes a gain medium having an optically-active phosphosilicate glass, wherein the phosphosilicate glass includes at least one active ion dopant and from about 1 to 30 mol % of phosphorus oxide. The phosphorous oxide may be present in an effective amount for reducing any photodarkening effect and increasing the saturation energy of the system. The active ion dopant may be a rare earth dopant. The light-emitting device may include an optical waveguide, the optical waveguide including the gain medium. The optical waveguide may have a core and at least one cladding, and the gain medium having the phosphosilicate glass may be found in the core and / or in one of the cladding.

The present invention relates to an optical amplification module having a construction which effectively suppresses photodarkening, and to a laser light source including the same. The laser light source comprises a light source for outputting light to be amplified, and an optical amplification module. The optical amplification module comprises two types of optical amplification media having different rare earth element concentrations, and a pumping light source. The low concentration medium and the high concentration medium are disposed in the propagation direction of pumping light such that the population inversion of the low concentration medium is higher than that of the high concentration medium. Hence, by arranging two types of optical amplification media with different rare earth concentrations such that the population inversion of the low concentration medium is higher than that of the high concentration medium, sufficient overall gain of the laser light source can be obtained while effectively suppressing photodarkening in the two types of optical amplification media.

A method for writing a Bragg grating in a rare-earth doped glass optical waveguide is provided. Ultrafast optical pulses are generated, preferably in the femtosecond range and having a writing wavelength in the range of 300 nm to 700 nm and an intensity sufficient to induce a change of refractive index in the rare-earth doped glass waveguide through densification. The optical pulses are diffracted using a phase mask, to generate an interference pattern having a pitch providing a fundamental Bragg resonance corresponding to the target wavelength to be reflected by the grating. The interference pattern is impinged on a region of the rare-earth doped glass waveguide, which is heated to a temperature above a threshold of about 350° C., for a predetermined heating period. Advantageously, the heating step allows the elimination of photodarkening effects which would otherwise be present in the waveguiding properties of the waveguide.

Photodarkening resistant optical fiber lasing media and fiber lasers incorporating the same are disclosed. In one embodiment, an optical fiber lasing medium includes a core portion formed from silica-based glass comprising a rare-earth dopant and deuterium, the core portion having an index of refraction nc, a numerical aperture NAc. A concentration of defect color centers in the core portion is less than 1×1016 / cm3. Deuterium is combined with the defect color centers to form reacted defect color centers that do not absorb ultraviolet and visible wavelengths of light. A first cladding portion is formed from silica-based glass, the first cladding portion surrounding and directly contacting the core portion and having an index of refraction n1, wherein the index of refraction n1 of the first cladding portion is less than the index of refraction nc of the core portion. Methods of forming the photodarkening resistant optical fiber lasing media are also disclosed.

The present invention relates to an optical amplifier module, or the like, having a structure for enabling effective suppression of photodarkening and efficient optical amplification. The optical amplifier module comprises a first optical amplification waveguide which is comprised of a phosphate glass as a main component and includes a ytterbium-doped first optical waveguide region, a second optical amplification waveguide which is optically coupled to the first optical amplification waveguide and includes a ytterbium-doped second optical waveguide region which is co-doped with aluminum, and pumping light source units which supply pumping light respectively to the first optical amplification waveguide and the second optical amplification waveguide. The light to be amplified, having inputted to the first optical amplification waveguide, is amplified only once by means of the pumping light, in each of the first optical amplification waveguide and the second optical amplification waveguide.

A very large more area active double clad optical waveguide doped with Nd3+ at a concentration of at least 0.1% by weight can be used to effectively amplify light at a wavelength of between 1050 nm and 1120 nm. At a doping concentration sufficient to provide a net optical absorption of at least 3 dB / m for the pump light at the wavelength of 795 to 815 nm or 883 to 887 nm, Nd3+ operates under much lower inversion levels than Yb3+. Due to the lower inversion levels, the Nd3+ doped waveguide is subject to reduced pump bleaching or photodarkening.

The invention discloses a photo-darkening test device for ytterbium-doped silica fiber with an all-fiber structure. The signal light output by the signal source passes through the optical fiber flange and the optical fiber attenuator in turn, and then passes through the pump light output by the first pumping source. The combined beam is synthesized by the wavelength division multiplexer; the combined beam and the pump light output by the second pump source are respectively input through the signal end and the pump end of the fiber combiner, and the output light of the fiber combiner is passed along the ytterbium-doped fiber For transmission, the output end of the ytterbium-doped fiber is fused with the input end of the cladding light stripper, and the output beam of the cladding light stripper enters the optical power detector through the low photon darkening filter fiber; the low photon darkening filter fiber is the doped Yb fiber; doped with Yb 2 o 3 The concentration is not higher than 0.1%wt. The beneficial effect of the invention is that the light-darkening test device has an all-fiber structure, the test system has a compact structure, the test method is simple, the device cost is low, the power of the signal source can be precisely adjusted, the test conditions can be optimized, and the test signal-to-noise ratio is high.

An optically active glass and an optical fiber comprising such glass, having reduced photodarkening properties are provided. The optically active glass is mainly composed of silica representing from about 50 to 98 mol % of the glass. It also includes at least one active ion, such as a rear-earth ion, which induces a photodarkening effect in optical properties of the glass. Moreover, the glass includes an effective amount of phosphorus oxide providing the photodarkening reducing effect, preferably in an amount of from about 1 to 30 mol %. A method for reducing a photodarkening effect in optical properties of an optically active glass including the step of introducing phosphorus oxide to the glass is also provided.

The invention discloses a photon darkening bleaching device to solve the current situation of lack of intervention in the photon darkening phenomenon in the operation process of the ytterbium-doped fiber laser. The invention includes a darkening bleaching light source and a driving power source thereof. The present invention adds a darkening and bleaching device inside the ytterbium-doped fiber laser, so the main structure of the fiber laser is not changed and has high applicability. The device of the invention is especially suitable for periodically bleaching the darkening of the fiber laser during work, which promotes the stability of the power of the fiber laser during use, slows down the photon darkening process of the laser, and improves the service life of the laser.

The invention relates to an anti-photodarkening ytterbium-doped silica fiber and a preparation method thereof. Specifically, the present invention provides an anti-photodarkening ytterbium-doped silica optical fiber, the glass of the optical fiber core rod at least includes Yb 2 o 3 、Al 2 o 3 ,P 2 o 5 , SiO 2 , where Yb 2 o 3 、Al 2 o 3 ,P 2 o 5 The proportions in the whole substance are: Yb 2 o 3 : 0.05~0.3mol%, Al 2 o 3 : 1~3mol%, P 2 o 5 : 1 to 5 mol%. The invention also provides a preparation method of an anti-photodarkening ytterbium-doped silica fiber. The present invention combines the sol-gel method and the improved chemical vapor deposition method, respectively utilizes its molecular-level doping uniformity and low-loss preparation advantages, effectively doping ytterbium ions, aluminum ions and phosphorus ions into the quartz matrix, effectively solving the problem of It solves the problems of high fiber loss, photodarkening due to clusters and other reasons, and the depression of the refractive index center.