Abstract
We demonstrate a tunable Q-switched Erbium-doped fiber laser (EDFL) using the newly developed titanium nanoparticles based saturable absorber (SA) for the first time. The Titanium nanoparticles were deposited onto the surface of polyvinyl alcohol (PVA) film via an electron beam evaporation process and inserted into an Erbium-doped fiber laser (EDFL) cavity to achieve passive Q-switching. A tunable bandpass filter was used in the EDFL cavity to tune the operating wavelength of the Q-switched EDFL from 1535 to 1565 mm At operating wavelength of 1535 nm, the repetition rate of the self-starting Q-switching pulses is increased from 18.3 kHz to 34.2 kHz while the pulse width is reduced from 19.4 to 10.45 vis with increasing pump power from 14.9 to 37.7 mW. The Q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 68 dB indicating the high stability of the laser. The highest pulse energy of 0.25 mu J was obtained with pump power of 37.7 mW at operating wave-length of 1565 nm. This is a simple and cost-effective light source for environmental sensing, metrology and biomedical diagnostics.