A tunable wavelength erbium doped fiber ring laser based on mechanically induced long-period fiber gratings

Abstract

A tunable wavelength erbium doped fiber ring laser, based on mechanically induced long-period fiber gratings (MLPFG) is presented. The laser was tuned applying pressure over the MLPFG, in order to control this, pressure is applied over a plate with periodic grooves that has a short length, this pressure is applied by a digital torque tester, as a result tunable effect is observed. The grooves have a period of 630μm and the maximal pressure without breakpoint fiber is around 0.80lb-in2. Furthermore, the MLPFG used can be erased, reconfigured and exhibit a transmission spectra with thermal stability, similar to high cost photoinduced long period gratings. In this work, by pressure increment distributed over the MLPFG from 0.20 lb-in2 to 0.50 lb-inμ, tuned operation range of 10nm was observed and single line emission was tuned between C and L telecommunications bands. According to the stability analysis the signal to noise ratio and linewidth observed were 35dB and 0.2nm respectively.