Harmonically mode-locked Ti:Er:LiNbO(3) waveguide laser

Waveguide resonator with an integrated phase modulator for second harmonic generation

We report second harmonic generation from a titanium indiffused lithium niobate waveguide resonator device whose cavity length is locked to the fundamental pump laser using an on-chip phase modulator. The device remains locked for more than 5 minutes, producing more than 80% of the initial second harmonic power. The stability of the system is seen to be limited by DC-drift, a known effect in many lithium niobate systems that include deposited electrodes. The presented device explores the suitability of waveguide resonators in this platform for use in larger integrated networks.

Efficient Nd:Ti:LiNbO3 ridge waveguide lasers emitting around 1085 nm

In this work, we report on efficient neodymium-doped titanium in-diffused ridge waveguide lasers in x-cut congruent LiNbO₃ under excitation at 814 nm. For the sample fabrication we used our novel technique of three-side evaporation and in-diffusion for Nd and Ti incorporation into pre-defined ridges. Due to improved photorefractive damage resistance by indium tin oxide (ITO) coating we achieved stable laser operation at 1084.7 nm with a maximum output power of 108 mW and a slope efficiency of 34% exceeding the best literature values for Nd:Ti:LiNbO₃ ridge waveguide lasers.

Effect of Defects on Spontaneous Polarization in Pure and Doped LiNbO₃: First-Principles Calculations

Numerous studies have indicated that intrinsic defects in lithium niobate (LN) dominate its physical properties. In an Nb-rich environment, the structure that consists of a niobium anti-site with four lithium vacancies is considered the most stable structure. Based on the density functional theory (DFT), the specific configuration of the four lithium vacancies of LN were explored. The results indicated the most stable structure consisted of two lithium vacancies as the first neighbors and the other two as the second nearest neighbors of Nb anti-site in pure LN, and a similar stable structure was found in the doped LN. We found that the defects dipole moment has no direct contribution to the crystal polarization. Spontaneous polarization is more likely due to the lattice distortion of the crystal. This was verified in the defects structure of Mg2+, Sc3+, and Zr4+ doped LN. The conclusion provides a new understanding about the relationship between defect clusters and crystal polarization.

Ion-implanted optical channel waveguides in neodymium-doped yttrium aluminum garnet transparent ceramics for integrated laser generation

We report, for the first time to our knowledge, on the fabrication of optical channel waveguides in neodymium-doped yttrium aluminum garnet transparent ceramics by oxygen implantation. The fabricated waveguides show reduced propagation losses (1.5 dB/cm), as well as the possibility of waveguide-mode tailoring. The confocal fluorescence images of the channel waveguides reveal that oxygen implantation causes only slight changes in the fluorescence properties of neodymium ions making the fabricated structures promising candidates for integrated laser sources in the infrared bands.