Long-period fiber grating devices packaged for temperature stability

摘要

The present applicants have discovered that one can fabricate a long-period grating wherein the grating peak wavelength lambda p will be shifted in different directions when the grating is subject to temperature and tensile strain, respectively. Accordingly, a long-period grating can be designed and packaged such that a temperature-induced shift in lambda p is compensated by a corresponding strain-induced shift arising from a single packaging material. Thus, by proper design of the grating and choice of the packaging material expansion coefficient, a temperature stable grating having temperature sensitivity of less than 4 nm per 100 DEG C. can comprise a grating fiber encased in or attached to a package comprising a single material such as glass, polymer or metal. Such designs permit the use of long-period grating devices without temperature control.