Distributed gain from multilayer photonic crystal fibers with negative-refraction materials.

Abstract??Distributed optical amplification from photonic-crystal fibers (PCFs) with layered structure composed of positive-and negative-refraction materials is studied by the finite-difference time-domain method. We found that the transmission spectra, with transmissivity far greater than unity at discrete transmission bands, have a band-gap structure with distributed gain, but the optical gain for defect modes is much smaller than that for transmitting modes, and maxima usually occur at the upper-and lower-band edges. This suggests that PCFs can be employed in dense wavelength-division multiplexed fiber-optics communication systems as transmission media carrying optical signals without crosstalk. [ABSTRACT FROM AUTHOR]