Optical fibers transmit light which is generally coupled out in the direction of the fiber. Fibers with shaped end surfaces work differently!
Sideways Beam
With side-fire fibers, it is possible to emit a laser beam at the fiber tip that is almost perpendicular to the fiber axis. The end surface of side-fire fibers features an angle of approximately 42°. The Brewster angle results in a total reflection, and the light is emitted sideways out of the fiber.
Our partner Polymicro Technologies produces side-fire fibers with the help of a CO2 laser. To prevent the sensitive fiber tips from breaking upon use, they are protected by a glass dome. This is hermetically mounted to the fiber tip with the CO2 laser as well.
Side-Fire Fibers in Medical Technology
Side-fire fibers are an important tool in laser medicine. They are used in the removal of tissue in hollow organs; for example, these fibers are used in the treatment of prostrate enlargements.
The diameters of these fibers and the glass dome are so small that they can be inserted into the body endoscopically without a problem until the area of treatment is reached. An SMA connector is normally mounted on the coupling side. Depending on the customers’ requirements, other connectors can also be used.
