Simple frequency tuning technique for locking asinglemode erbium-dopedfibre laser to the centre of molecular resonances

Abstract
The authors report a Fabry-Perot erbium fibre laser which displays a single-longitudinal mode and tuning capability over 21 nm with a frequency resolution of ~20 MHz. The laser can also be piezoelectrically frequency-modulated with a frequency deviation up to 25 GHz. A small frequency modulation is applied to lock the laser to the centre of the R(10) line of acetylene at 1527.862(4) nm.