Patent DE-102009009094-A1 (DE)
Title: Fiber laser comprises a pump fiber, which is coupled at a tube-shaped body made of transparent material as a carrier or a layer to the jacket surface of the carrier so that the pump radiation is coupled into the body
Inventor: STEIGER BERNHARD
IPC: H01S3/067
Filed: 2009-02-12
Abstract: The fiber laser comprises a pump fiber (2), which is coupled at a tube-shaped body (3) made of transparent material as a carrier or a layer to the jacket surface of the carrier so that the pump radiation is coupled into the body and is guided as a medium in the body, and an active fiber (4), which is disposed in a screw form and is partially disposed in or on the body, so that the laser radiation is generated in the body. The active fiber exists itself in the tubular body so that the active fiber is crossed by the pump radiation in the body. The fiber laser comprises a pump fiber (2), which is coupled at a tube-shaped body (3) made of transparent material as a carrier or a layer to the jacket surface of the carrier so that the pump radiation is coupled into the body and is guided as a medium in the body, and an active fiber (4), which is disposed in a screw form and is partially disposed in or on the body, so that the laser radiation is generated in the body. The active fiber exists itself in the tubular body so that the active fiber is crossed by the pump radiation in the body and the laser radiation is generated in the active fiber. The active fiber is disposed in or on the body so that the active fiber is coupled over the evanescent field of electromagnetic radiation in the body and the laser radiation is generated in the active fiber. The body is a layer on a rod- or tube-shaped carrier, where the thickness of the layer is smaller, equal or larger than the diameter of the active fiber. An intermediate layer is arranged between the jacket surface of the carrier and the layer. The refractive index of the intermediate layer is smaller than the layer so that the pump radiation of the layer is reflected on the intermediate layer. The body has a spirally arranged groove with the active fiber. The pump fiber is coupled on the front side or the cover area of the body. A cover layer is arranged on the body and/or the active fiber. The refractive index of the cover layer is smaller than the body and the active fiber so that the pump radiation of the body and contingently generated laser radiation are reflected on the cover layer. The front area of the body is mirrored. The end areas of the active fiber are mirrored or have a bragg grating so that the active fiber is a resonator. The refractive index and the geometric mass of the respective media are implemented so that they are implemented over total reflexion at the respective boundary areas of the pump radiation as also the produced laser radiation. The body or the carrier is coupled with the layer as body with or on the cooling mechanism. The active fiber is a monomode fiber with an active core. An area of the pump fiber or the active fiber in the cross-section is a circle section. The electromagnetic radiation is coupled to the pump fiber as delivering source. The body is made of glass or plastic and the carrier is made of glass, plastic, metal, metal alloy, ceramics or graphite and the intermediate layer or the cover layer is made of glass or plastic.