A solid-state laser system includes a gain medium having an optical resonator defined therein. The gain medium is co-doped with first and second active elements. The first active element is Er.sup.3+ and the second active element is Ho.sup.3+ or Dy.sup.3+. The solid-state laser system also includes a pump source coupled to the gain medium for pumping the gain medium with pump light.

An ultraviolet laser apparatus includes: a semiconductor laser that emits an excitation laser light; a fiber laser medium to which the excitation laser light enters from the semiconductor laser and that causes laser oscillation; and an external resonator that: converts a wavelength of a laser light oscillated in the fiber laser medium, and outputs an ultraviolet region continuous wave of at least 0.1W.

A rare earth-doped optical fiber comprises a fluorosilicate core surrounded by a silica cladding, where the fluorosilicate core comprises an alkaline-earth fluoro-alumino-silicate glass, such as a strontium fluoro-alumino-silicate glass. The rare earth-doped optical fiber may be useful as a high-power fiber laser and/or fiber amplifier. A method of making a rare earth-doped optical fiber comprises: inserting a powder mixture comprising YbF.sub.3, SrF.sub.2, and Al.sub.2O.sub.3 into a silica tube; after inserting the powder mixture, heating the silica tube to a temperature of at least about 2000° C., some or all of the powder mixture undergoing melting; drawing the silica tube to obtain a reduced-diameter fiber; and cooling the reduced-diameter fiber. Thus, a rare earth-doped optical fiber comprising a fluorosilicate core surrounded by a silica cladding is formed.

A mid-infrared semiconductor saturable absorber mirror based on InAs/GaSb superlattice comprises a GaSb substrate with an anti-reflection film coated on the lower surface of the GaSb substrate; InAs/GaSb superlattice which has a specific structure and thickness and is arranged on the GaSb substrate; and Bragg reflection film which is arranged on the InAs/GaSb superlattice, wherein Bragg reflection film is composed of multiple pairs of ZnS and YbF.sub.3 film layers with a thickness of ¼ wavelength, and the YbF.sub.3 film layer is connected with the InAs/GaSb superlattice. The device not only has a mid-infrared working range with a broadband operation bandwidth, but also has the advantages of designable parameters, outstanding robustness, high damage threshold and the like, and sets a foundation for the development of mid-infrared ultrafast mode-locked lasers.

In an optical fiber device having a configuration in which an optical fiber is joined to a side surface of another optical fiber, a joint portion is suppressed from reaching a high temperature. The optical fiber device includes a first fluoride fiber, a second fluoride fiber, and a heat dissipation member. The first fluoride fiber guides light. The second fluoride fiber has a first end on or from which light is incident or output and a second end at which an end surface of the second fluoride fiber is obliquely joined to a side surface of the first fluoride fiber.

The technology of this application relates to the field of communication technologies, and an optical fiber raw material composition, an optical fiber, and an optical fiber product. The optical fiber raw material composition includes components of the following molar percentages: AlF.sub.3 10%-50%, BaF.sub.2 3%-20%, CaF.sub.2 3%-20%, YF.sub.3 1%-15%, SrF.sub.2 3%-20%, MgF.sub.2 3%-20%, and TeO.sub.2 1%-35%. The optical fiber prepared by using the optical fiber raw material composition provided in this disclosure can be used in aspects such as a mid-infrared band transmission optical fiber, an optical fiber amplifier, a fiber laser, and an optical fiber sensor.

A ring cavity laser source, a tunable ring cavity laser source and a method of fabricating a ring cavity laser source. The fiber ring cavity laser source comprises a fiber pigtailed pump laser; a fiber-based gain medium; a fiber-based circulator; a fiber-based coupler, wherein an input fiber port of the fiber-based coupler is coupled to a first end of the fiber-based gain medium, a first output fiber port of the fiber-based coupler is coupled to a first fiber port of the fiber-based circulator, and a second output fiber port of the fiber-based coupler is configured for extracting a laser output of the fiber ring cavity laser source; a fiber-based reflector coupled to a second fiber port of the fiber-based circulator; and a fiber-based combiner, wherein a first input fiber port of the fiber-based combiner is coupled to the fiber pigtailed pump laser, a second input fiber port of the fiber-based combiner is coupled to a third fiber port of the fiber-based circulator, and an output fiber port of the fiber-based combiner is coupled to a second end of the fiber-based gain medium; wherein the fiber-based reflector is configured for wavelength tuning of the laser output.

A fiber laser apparatus includes: a short-length type fiber to which an active element is added and that has a length of 300 mm or less: a ferrule attached to an end of the fiber; and a housing that accommodates the fiber and supports the fiber with the ferrule. Each of the housing and the ferrule is composed of a material having a first thermal expansion coefficient that is equal to or have a predetermined difference from a second thermal expansion coefficient of a raw material of the fiber. The predetermined difference between the first and second thermal expansion coefficients is within −8.6×10.sup.−6 to 11.4×10.sup.−6/K.

A laser device is provided that includes an element made of laser-active material and a cladding element bonded to the element so as to allow heat exchange by heat conduction between the cladding element and the element. The laser-active material emitting laser light when excited by pump light. The element being made of a glass. The cladding element being made of a material that exhibits an absorption coefficient for the pump light that is lower than a corresponding absorption coefficient of the glass. The element and cladding element being configured so that the pump light can be directed through the cladding element into the element and/or so that the pump light can be directed through the element into the cladding element.

A fiber laser apparatus includes: a short-length type fiber to which an active element is added and that has a length of 300 mm or less: a ferrule attached to an end of the fiber; and a housing that accommodates the fiber and supports the fiber with the ferrule. Each of the housing and the ferrule is composed of a material having a first thermal expansion coefficient that is equal to or have a predetermined difference from a second thermal expansion coefficient of a raw material of the fiber. The predetermined difference between the first and second thermal expansion coefficients is within −8.6×10.sup.−6 to 11.4×10.sup.−6/K.