ABSTRACT
Hybrid glass substrates were prepared by a novel, low-temperature process joining active (Er-Yb codoped) and passive phosphate glass. The resulting hybrid substrates are chemically and physically robust; they can be cut, ground, and polished by conventional, water-based techniques. The entire substrate can be immersed in a molten-salt bath to produce waveguides simultaneously in the active and passive regions. A low reflectance of -34+/-2 dB was measured at the joint interface with 1531.2-nm light by optical low-coherence reflectometry. Further, a hybrid laser waveguide device exhibited a slope efficiency of 33% at 1540 nm when pumped at 975 nm.
ABSTRACT
Waveguide lasers operating near 1092 and 1076 nm were fabricated in Z-cut Nd-Ti codiffused LiTaO(3). The Nd diffusion was at 14000 degrees C for 120 h. Samples from two wafers were examined. The Nd film starting thickness was 7 nm in wafer 1 and 15 nm in wafer 2. Ti stripes, 8-15 microm wide, were diffused at 1500 degrees C for 4 h for wafer 1 (130-nm stripe thickness) and 2 h forwafer 2 (100-nm stripe thickness). Pumping was at 750 nm. Threshold occurred at 330 mW of absorbedpump power for the best waveguides from wafer 1 and100 mW for the best waveguides from wafer 2. The slope efficiency of the latter was 0.07%.
