Where to Buy Double-clad Fibers

• What kind of laser-active dopant do you need – Er³⁺, Yb³⁺, Nd³⁺, Tm³⁺ or anything else?
• Can it be a kind of silica fiber, or do you require some specialty glass, e.g. a fluoride fiber?
• What doping concentration do you need? Alternatively, manufacturers often specify the absorption at some given wavelength(s) – for the core or for the pump cladding.
• What is the fiber's quality? Is the power conversion efficiency reduced by quenching effects and the like?
• What is the effective mode area or mode radius of the fiber core? (There are special large mode area fibers.)
• (For single-mode fibers, the core diameter and numerical aperture are usually not relevant, if the mode area is known.)
• (The propagation losses are usually not very relevant, except if an unusually long length of fiber is used.)
• What is the diameter and numerical aperture of the pump cladding?
• Is the pump cladding circular, elliptical or D-shaped?
• How tight bending is possible, before the bend losses become too high?
• How much optical average power can the fiber tolerate? (Additional properties at the launch end may still occur if too much power gets to the coating.)
• What is the outer fiber diameter with and without protective coating?
• What is the coating material? Is it a standard material which can be removed with a usual fiber stripper?
• Can the fiber be cleaved with a standard fiber cleaver? (Fluoride fibers, for example, have quite different mechanical properties than silica fibers.)
• Are there fiber couplers available for combining pump and signal inputs, or for separate pump and signal at the end?

Also have a look at the check lists for rare-earth-doped fibers and for general fibers.

In case that you need additional advice, consultancy from RP Photonics may be the solution.