Abstract: An optical fiber preform comprising a plurality of longitudinal air holes is subjected to a thermal treatment (i.e., heating), coupled with the application of a compressive force on either end of the heated preform to compress the entire preform structure a predetermined amount. The thermal compression treatment has been found to smooth any roughened glass surfaces and heal microcracks that may have formed during the preform fabrication process, essentially “knitting” the glass material back together and forming a preform of improved quality over the prior art microstructured preforms.

Abstract: An optical fiber preform comprising a plurality of longitudinal air holes is subjected to a thermal treatment (i.e., heating), coupled with the application of a compressive force on either end of the heated preform to compress the entire preform structure a predetermined amount. The thermal compression treatment has been found to smooth any roughened glass surfaces and heal microcracks that may have formed during the preform fabrication process, essentially “knitting” the glass material back together and forming a preform of improved quality over the prior art microstructured preforms.

Abstract: An optical fiber preform comprising a plurality of longitudinal air holes is subjected to a thermal treatment (i.e., heating), coupled with the application of a compressive force on either end of the heated preform to compress the entire preform structure a predetermined amount. The thermal compression treatment has been found to smooth any roughened glass surfaces and heal microcracks that may have formed during the preform fabrication process, essentially “knitting” the glass material back together and forming a preform of improved quality over the prior art microstructured preforms.

Abstract: An in-line, distributed optical fiber filter comprises a core region with a raised refractive index (with respect to the surrounding cladding material) so as to allow for total internal reflection (TIR) of the desired transmission wavelength(s). One or more raised index features are formed within the cladding region and are configured so as to result in mode mixing between the cladding mode and core mode at determined wavelength(s) to be removed by filtering. The parameters associated with determining the proper core specifications and cladding specifications can be separately determined to provide for enhanced performance in terms of both filtering unwanted signals and propagation of desired communication signals.

Abstract: A photonic band gap fiber structure is formed to include a plurality of filled air holes surrounding a solid silica core region. The material used to fill the air holes is chosen to exhibit an index of refraction that is greater than the index of the core, where the fill material refractive index is also adjustable as a function of temperature. Therefore, by adjusting the temperature of the PBG fiber, the dispersion characteristic of the propagating signal can be modified.