A temperature sensor with circular confined thermal bimetal sheets

based on improved optical fiber Fabry-Perot（F-P） cavity is introduced.The scheme is based upon F-P interference

the F-P cavity is composed with one polished surface of bimetal and one polished end face of optical fiber inserted in a common flange optical fiber connector.The finite element snalysis（FEA） results for the ring confinements are given;the size of the ring hole can be simply changed to agilely meet the requirement of the different measurement range;the F-P temperature sensors with the developed bimetal sheets confinement mechanism are designed and fabricated

the practical measurements are carried out.