Articles by FOC FAQ

QUESTION: Do you have a process for making double-clad fibers? ANSWER: Yes. In addition to providing process information on the Halide system, we can also provide process information on preform fabrication, stretching and sleeving operations, preform shaping,...

QUESTION: Do you provide process information for running the Halide system? ANSWER: Yes, we will provide the process information and instruction required to prepare a batch of anhydrous rare earth chloride, and a typical process recipe for an industry standard Yb...

QUESTION: What about OH incorporation, background loss? ANSWER: The OH incorporation in the core glass is typically about ¼ of a PPM which will give a water peak at 1380 nm of approximately 15 dB/km. The background loss of the fiber in the windows where the rare...

QUESTION: How do you control the concentrations of the various dopants? ANSWER: Concentrations of the dopants used in the Halide system are controlled using gas flow rates as well as temperature, just as is done with the standard MCVD system.    ...

QUESTION: How do these fibers perform with respect to photo-darkening? ANSWER: Photo-darkening of Yb doped fibers depends not only on the doping process used but also on the composition of the fiber. We offer a photo-darkening preform recipe to be used with the...

QUESTION: What kind of laser or amplifier performance can be expected from fibers made with the Halide Process? ANSWER: For Er doped fiber used in EDFA’s pumped at 1480 nm, efficiencies of ≈ 69% with optical gain of ≈ 35 dB have been demonstrated at 1550 nm....

QUESTION: Which rare earths can be deposited by Halide process? ANSWER: Rare earth elements that have been demonstrated are Ytterbium, Erbium, Thulium, Holmium, Neodymium and Cerium. Since most of the elements in the Lanthanide series exhibit identical chemical...

QUESTION: Can we prepare multi element rare earth anhydrous boats? ANSWER: Yes. This can be done by mixing the precursor rare earth compounds when preparing a halide batch. The most relevant application that comes to mind is the fabrication of Er/Yb doped...

QUESTION: What wt. % of rare earth is possible in the fiber? ANSWER: For preforms requiring high concentration, values of Tm3+ have been reported at ≈ 8.5 wt.%. This is by no means the limit of what is achievable.      Answered by AskFOC Fiber...

QUESTION: How long does the anhydrous rare earth in the quartz boat last? ANSWER: A charge of rare earth material will last for at least 1 week and could last as long as several weeks depending on the number of preforms produced and the rare earth concentration...