HEAT-TRANSFER MODELING IN CO2-LASER PROCESSING OF OPTICAL FIBERS

The diameter self-regulation of optical fibre tapers produced using a CO2 laser has been examined theoretically and modelled numerically. Re sults of the simulation show that for small diameters, where the geome tric model of absorption cannot be used, the Mie theory of absorption derived from the Maxwell equations exhibits structure due to resonance s of the CO2 laser radiation in the tapered fibre. At small diameters, the polarisation state of the CO2 laser is important, and resonance e ffects cause the equilibrium temperature/diameter graph to exhibit osc illations. (C) 1998 Elsevier Science B.V. All rights reserved.