Abstract: An optical fiber connector for transmitting high optical power, specifically power exceeding 1 kW. The connector includes an optical fiber having one of its ends in direct optical contact with a body made of a transparent material. The body in connection with the optical fiber end has a surface with an area exceeding the contact surface area of the optical fiber. The surface of the transparent body has a substantially conical design in order to provide an efficient flowing geometry around the contact end of the fiber, to increase the surface area for incident power loss radiation and deviate such radiation towards the optical axis of the connector.

Abstract: An optical fiber contact for transmitting moderate-magnitude optical power. The fiber contact includes an optical fiber having an inner core and a surrounding cladding for transmitting the radiation in the core. Additional surrounding layers including so-called buffer and jackets mechanically stabilize the optical fiber. The forward part of the optical fiber contact is surrounded by a transparent tubular member. The tubular member extends a certain length along the outer cylindrical surface of the cladding. There is no heating by power loss radiation, as the power loss radiation is leaving the contact as optical radiation. To disperse radiation propagating within the cladding, the cladding includes a roughening or additional layers of a transparent material. In case of additional layers of transparent material then the outermost layer should be roughened.

Abstract: A device for cooling optical components based on optical fibers for transmitting high optical power. The device includes one or more cavities with a flowing coolant to take care of optical power loss. The device includes a transmitting construction material having a low heat expansion coefficient arranged in direct connection with the optical components and arranged to transmit power loss radiation into the cavity which is flushed with the flowing coolant. The transmitting construction material is made as a transparent tube and surrounded by a tubular casing of a non-transparent material having a good absorption capacity so that the cavity is formed between the two materials.

Abstract: A device for cooling optical components based on optical fibers for transmitting high optical power. The device includes one or more cavities with a flowing coolant to take care of optical power loss. The device includes a transmitting construction material having a low heat expansion coefficient arranged in direct connection with the optical components and arranged to transmit power loss radiation into the cavity which is flushed with the flowing coolant. The transmitting construction material is made as a transparent tube and surrounded by a tubular casing of a non-transparent material having a good absorption capacity so that the cavity is formed between the two materials.

Abstract: An optical fiber contact for transmitting moderate-magnitude optical power. The fiber contact includes an optical fiber having an inner core and a surrounding cladding for transmitting the radiation in the core. Additional surrounding layers including so-called buffer and jackets mechanically stabilize the optical fiber. The forward part of the optical fiber contact is surrounded by a transparent tubular member. The tubular member extends a certain length along the outer cylindrical surface of the cladding. There is no heating by power loss radiation, as the power loss radiation is leaving the contact as optical radiation. To disperse radiation propagating within the cladding, the cladding includes a roughening or additional layers of a transparent material. In case of additional layers of transparent material then the outermost layer should be roughened.

Abstract: An optical fiber connector for transmitting high optical power, specifically power exceeding 1 kW. The connector includes an optical fiber having one of its ends in direct optical contact with a body made of a transparent material. The body in connection with the optical fiber end has a surface with an area exceeding the contact surface area of the optical fiber. The surface of the transparent body has a substantially conical design in order to provide an efficient flowing geometry around the contact end of the fiber, to increase the surface area for incident power loss radiation and deviate such radiation towards the optical axis of the connector.

Abstract: The present invention relates to a method and a device for detecting damages in an optical fibre (1,2) made for transmitting high optical power, specifically power exceeding 1 kW, and where the optical fibre (1,2) has an entrance end (7) for incident optical radiation (4) and an exit end where the optical radiation is leaving the fibre. According to the invention substantially radially spread radiation in connection with the entrance and/or exit parts of the fibre is detected, and if this radiation exceeds a certain level this is used as an indication of a damage in the entrance and/or exit zone of the fibre.

Abstract: A method and apparatus for measuring the power loss in a fiber optical connector of the type which includes an optical fiber for transmitting high optical power, specifically power exceeding 1 kW. Incident radiation falling outside the fiber core is absorbed at least partially in a flowing coolant. The connector includes thermo-elements for measuring a temperature difference between the ingoing and outgoing coolant as a measure of the generated power loss. The flow speed may be adapted to different power losses.

Abstract: The present invention relates to a method and a device for detecting damages in an optical fibre (1,2) made for transmitting high optical power, specifically power exceeding 1 kW, and where the optical fibre (1,2) has an entrance end (7) for incident optical radiation (4) and an exit end where the optical radiation is leaving the fibre. According to the invention substantially radially spread radiation in connection with the entrance and/or exit parts of the fibre is detected, and if this radiation exceeds a certain level this is used as an indication of a damage in the entrance and/or exit zone of the fibre.

Abstract: The invention relates to a method and means for measuring the power loss in a fibre optical connector of the type which includes an optical fibre (3) for transmitting high optical power, specifically power exceeding 1 kW, and wherein incident radiation (1) falling outside the fiber core is absorbed at least partially in a flowing coolant (2). The connector comprises means, for instance thermo-elements (8), for measuring the temperature difference (&Dgr;T) between the in- and outgoing coolant as a measure of the generated power loss. Preferably the flow speed is adapted to different power losses.

Abstract: An apparatus for determining the position of the focal point of a laser beam in a laser machining system in which the laser beam is transmitted via an optical fiber to the work-piece to be machined by the laser beam. The z coordinate position of the focal point is determined by a mirror for reflecting some of the laser radiation back towards the end surface of the optical fiber, and a detector is arranged between the laser and the outgoing fiber for measuring the radiation reflected back through the fiber.

Abstract: An optical fiber cable of the type comprising a fiber (3) having a central core and a surrounding cladding and made for transmitting optical high-power, specifically power exceeding 1 kW. At least one of the fiber ends is provided with cooling means for optical power loss comprising a cavity with a flowing coolant (2) surrounding the envelope surface of the fiber end. Incident radiation that falls outside the fiber comes into the coolant, preferably a liquid coolant such as water, where it is at least partially absorbed. At least one of the limiting wall surfaces of the cavity is completely or partially non-absorbing for the incident radiation, while the other limiting wall surfaces are arranged to absorb such radiaton that is still present and transmitted through the flowing coolant (2). As these surfaces are in direct contact with the coolant an efficient cooling is obtained.

Abstract: An optical fiber cable for high power laser radiation transmission comprises a fiber having a core and a surrounding cladding, a rod provided at at least one of contact ends of the core and fused to an end surface of the core the rod having larger diameter than that of the core, and a reflector provided at this end of the fiber, the rod being designed to conduct rays entering outside the fiber towards an area where they can be absorbed without causing any damage, to conduct rays not linked into the fiber towards the reflector.

Abstract: An optical fiber for high-power laser transmission is formed of a glass fiber with a fiber core and a fiber cladding surrounding the fiber core. An intermediate layer of polymer is disposed on the fiber cladding, a metallic coating of film is disposed on the intermediate layer, and the metallic coating is protected against mechanically induced damage with an outer jacket. The operational condition of the optical fiber is monitored in that the electrical resistance across the metallic coating is measured along the optical fiber. When the resistance exceeds a predetermined threshold value, the laser radiation is prevented from entering the optical fiber, preferably with a shutter.