Polarim Etri C Fi Be R-op Ti C Sy Ste M for Stati C a Nd Dy Nam Ic Stra in M Ea Sure M Ent

F iber-opti c sensi ng systems are being presentl y tested in a vari ety of smart str uctures and ski ns appl icati ons [1{ 4]. In parti cul ar , po lari m etri c sensors wi t h hi ghly bi ref ringent (HB) polarizati on-m ainta ini ng opti cal Ùbers have focused a great interest for use in conjuncti on wi th com posite m ateri als. Thi s growi ng interest has been mainl y m ani fested in successful appl icati ons of HB Ùbers into Ùber opti c sensors based on polari m etri c interf erence [4]. An inÛuence of a vari ety of physi cal param eters on the mode propagati on in HB Ùbers is of special importa nce, since a num ber of physi cal quanti ti es can be measured on the basis of the Ùbers. R ecently, the sui tabi l i ty of HB few-mode Ùbers for the m easurement of hydro stati c pressure, twi st, and stati c and dyna m ic stra in has been successful ly demonstra ted [4{ 9]. There is at present much ẽ o rt to appl y polari m etri c Ùber-opti c sensors to m easure stra in in ai rcra ft or concrete structure s usi ng a concept of so-cal led smart skins and structure s. Smart structures or smart skin are structura l components wi th netwo rks of Ùber opti c sensors embedded in the com posite materi al m atri ces. The com posite materi als are m ade from epoxi es or polyi mides. A m ore am bi tio us and com plex use of smart structures inv olves l inki ng Ùber opti c sensors wi th the realti m e com putercontro l system s. In thi s m odel , Ùber-opti c sensors are embedded in a panel to be integrated wi th the pl ane wi ng or the constructi on. The sensors moni to r envi ronm enta l e ̃ects such as stra in and bendi ng. In response to