Patent ID: 6376830
Filing Date: 2002-04-23
Classification: G01M

Abstract:
For an N-port guided wave device having a maximum effective path length LD and an effective index n, the guided wave device being defined by a transfer function matrix having NÃ—N scalar transfer function elements, a system for measuring each of the NÃ—N transfer function elements comprising:a tunable source for generating optical energy of a selected wavelength; first means coupled to said source for directing said optical energy along N reference paths and for producing N reference signals indicative of amplitude, phase and frequency of said optical energy carried along said N reference paths; second means coupled to said source for directing said optical energy to the N-ports of the guided wave device, wherein a portion of said optical energy is modified in terms of at least one of said amplitude and said phase to produce N2 modified signals; third means coupled to said first means and said second means for combining each of said N2 modified signals with a corresponding one of said N reference signals to produce corresponding N2 combined signals; fourth means coupled to said tunable source and said third means for sampling each of said N2 combined signals at a wave number increment &Dgr;k , wherein corresponding N2 sampled signals are produced; said first means defining N reference path lengths LRi, i=1 to N, and said second means and said third means defining N combined path lengths LMj, j=1 to N, for each of said N reference paths, wherein |LRiâ€”LMi|>N*LD |j=1,N |i=1,N and &LeftBracketingBar;LRi-LMi&RightBracketingBar;+LD<Ï€2&it;n&it;â€ƒ&it;Î”&it;â€ƒ&it;k&RightBracketingBar;j=1,N&RightBracketingBar;i=1,N,and wherein N combined signals of said N2 combined signals that are associated with said corresponding one of said N reference signals are spatially separated from one another in the time domain; anda processor coupled to said fourth means for generating the NÃ—N transfer function elements of the transfer function matrix using said N2 sampled signals.