[4] [4] Bhatia V,Vengsarkar A M. Optical fiber long-period grating sensors.Opt Lett, 1996,21(9):692～694

[5] [5] Rao Y J,Wang Y P,Ran Z L,et al.Novel fiber-optic sensors based on long-period fiber gratings written by high-frequency CO2 laser pulses.J of Lightwave Technology, 2003,21(5): 1320～1323

[6] [6] Liu Y,Zhang L,Whllams J A R,et al.Optical bend sensor based on measurement of resonance mode splitting of long-period fiber grating. IEEE Photonics Technol Lett, 2000,12(5):531～533

[7] [7] Rao Y J,Wang Y P,Ran Z L,et al. Characteristics of novel long-period fibre gratings written by focused high-frequency CO2 laser pulses. Asia-Pacific Optical and Wireless Communications 2001, Proc SPIE, 2001,4581: 327～333

[8] [8] Patrick H J,William G M,Kersey A D,et al.Hybrid fiber bragg grating/long period fiber grating sensor for stain/temperature discrimination.Photonics Technology Letters, 1996,8(9):1223～1225

[9] [9] Melle S M,Liu K,Measures R M.A passive wavelength demodulation system for guided-wave Bragg grating sensors. IEEE Photon Techno Lett,1992,4(5):516

[10] [10] Liu Y,Zhang L,Bennion I.Arbitrary spectral response fibre edge filters based on tilted chirped grating structures.CLEO ′99, Lasers and Electro-Optics, 1999: 297

[11] [11] Cooper D J F, Smith P W E.Simple and highly sensitive method for wavelength measurement of low-power time-multiplexed signals using optical amplifiers.Lightwave Technology, 2003,21(7): 1612～1620