Evolution of silica-based highly nonlinear fibers for FWM-based wavelength conversion application
Recent progresses on silica-based highly nonlinear fibers for practical FWM-based applications such as wavelength conversion efficiency enhancement and chromatic dispersion design are described, and then functional wavelength conversions using the fibers are demonstrated.
Broadband wavelength conversion over 193-nm by HNL-DSF improving higher-order dispersion performance
Four-wave-mixing-based wavelength conversion over 193-nm bandwidth, fully covering from S- to U-bands, is demonstrated by a 100-meter-long HNL-DSF with improved β4 of 10-56 s4/m and zero-dispersion wavelength fluctuation within ±0.1 nm. (2 pages)
Mathematical Time and Physical Time in the Theory Of Relativity
In the Theory of Relativity time is an imaginary quantity that can not be observed; it is a multiplication of a number that indicates duration of material change and number i that is an imaginary number. i on the square is -1. Time i⁄t is a mathematical time that describes the speed and the duration of material change. In the Universe one can observe physical time only as a stream of material change. It is not that change run in physical time, change itself is physical time.. Distinction between imaginary mathematical time and visible physical time opens some new perspectives into interpretation of Theory of Relativity. c