2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93766The potential of twin photons generated by parametric down-conversion for metrological applications are discussed. We present several experimental results like the measurement of chromatic dispersion and polarization mode dispersion in optical fibers.6 pages, 5 figures, Invited paper for the Symposium on Optical Fiber Measurements, sponsored by NIST, Boulder, Co, September 15-17, 1998Quantum Physicstext