Quasi-distributed strain sensor incorporating a chirped Moire/spl acute/ fiber Bragg grating

A quasi-distributed strain sensor with an average spatial resolution of 164 μm over a length of 25 mm and a strain sensitivity of 0.8/spl plusmn/0.01 pm/μ/spl epsiv/ has been experimentally demonstrated. The sensor was formed by a chirped Moire/spl acute/ fiber Bragg grating written into the core of single-mode optical fiber with a 244-nm continuous-wave laser.