Glass Processing Solutions at Timbercon
Glass processing solutions allow for better control beam characterization to suit specific fiber or fiber-laser application needs. There are different customized glass processing products and solutions, including ball lenses, end caps, axicon probes and tapers. Glass processing solutions allow you to diverge or converge a light beam, giving better control of spot size, focal length, numerical aperture or power density.
Glass Processing Solutions
At Timbercon, our capabilities in specialized splicing include the ability to splice dissimilar fiber optics. The dissimilar fiber optics can include fibers of different diameters, different geometries and different materials. What might this look like? With different diameters, an example would be a 125 micron fiber diameter spliced to a 600 micron fiber diameter. For different fiber geometries, it may be a photonic crystal (or holey fiber) and a standard step index fiber. With different materials, you might see a fiber made of ZBLAN and one made of fused silica, which have different melting points.
Overcladding is the process of fusing a glass capillary or tube over the outside of a fiber optic. This would be done to add another layer of glass with a different index of refraction or to create a mechanical anchor on the outside of the fiber optic.
The benefit or purpose of overcladding could be to increase the mechanical strength, strip or remove unwanted light (known as cladding modes), or create a sealed alignment to other optics within the capillary.
Tapering is the process of stretching the fiber into a smaller diameter. This is used for matching fibers of different diameters or getting light into cladding for sensing. This process saves fiber area, drawing light down to a smaller fiber.
In sensors when light gets tapered down a single mode, the waveguide still guides even though the light is too big to fit in the fiber. The signal is traveling along the fiber but part of the wave is existing outside the fiber.
Fiber Optic End Capping
The tips of optical fiber can be transformed to various lens shapes. Ball lenses can be used in a variety of applications such as medical laser, imaging, military applications, laser coupling, optical switching, sensing, ablation and various research and development. The focal distance and radius of the ball can be constructed in such a way as to create converging, diverging or a collimated beam exiting the ball.
Conventional End Cap
As high-powered fiber lasers become more and more prevalent, end cap technology has become more and more imperative. The extremely high energy density of the output end of a fiber laser can cause reliability issues. End caps allow the high density energy to diverge in a controlled manner. The end cap diameter can be 4 to 8 times larger than the actual fiber output from the laser.
Where Glass Processing Can Be Used
The glass processing solutions described above can be used in a variety of applications in the industrial and medical fields.
For industrial applications, most often glass processing is used for high power applications and components used in construction. With high power applications, the fusing on end caps can reduce power density for high power laser light. The creation of high power fiber lasers is where combiners can come into play for construction uses.
In the medical world, OCT probes utilize end capping and glass processing. Tapered probes can be used to detect antigen, protein or antibodies, while ball lenses use focused high power laser light to treat kidney stones.
Kylan Hoener is a field application engineer (FAE) at Timbercon, specializing in optical design.