Grating reflectors for erbium-doped lithium niobate waveguide lasers

摘要

Abstract: A grating fabrication technology has been established for producing DFB- /DBR-grating structures in Er-doped Ti:LiNbO$-3$/ waveguide lasers. It is based on holographically defined resist gratings transferred into the surface of LiNbO$-3$/ waveguides using reactive ion etching with SF$-6$/ gas as the dry etching technique. For a sample with a 24 mm long surface relief grating of 346 nm period, a transmission drop of $MIN@11.7 dB, a filter bandwidth as small as 0.08 nm, a Bragg resonance wavelength at 1528.4 nm very close to the Erbium absorption line at 1531 nm and excess losses attributed to the grating of only 1 to 2 dB were measured. !22