Nanosecond pulse erbium-doped fiber laser based on evanescent field interaction with lutetium oxide

Abstract

The mechanism of evanescent field interaction is established between lutetium oxide (Lu2O3) and light on the surface of D-shaped optical fiber. The D-shaped optical fiber was prepared using rotating wheel technique with the improved two times polishing method. The side-polished fiber sample owns a remaining fiber diameter of 70 μm and polishing length of 1400 μm. Lutetium oxide was deposited onto the D-shaped optical fiber as a pulse initiator inside an erbium-doped fiber laser cavity. A Q-switched with operating wavelength of 1565 nm was generated. Stable pulses were recorded as the pump power raised from 146 to 162 mW with pulse width as short as 450 ns and repetition rate of 0.967 MHz. As the pump power varied, output power of 120 to 160 μW which corresponds to pulse energy of 124 to 166 pJ were obtained.