Chuan-Lei Jia

Formation of c-axis oriented ZnO optical waveguides by radio-frequency magnetron sputtering

ZnO/Mg0.16Zn0.84O (ZnO/MgZnO) films are fabricated on x-cut and z-cut LiNbO3 (LN) substrates by radio-frequency magnetron sputtering. High transparencies are confirmed by a spectrophotometer. X-ray diffraction (XRD) spectra show that all the films are c-axis oriented. The waveguiding properties, as well as the refractive indices and thickness of the films are demonstrated and determined by prism coupling. Both transverse electric (TE) and transverse magnetic (TM) modes are measured at lambda=0.633 mum and 1.539 mum, respectively. The waveguide loss is measured at lambda=0.633 mum with a fiber probe technique. The experimental results show that high optical quality ZnO films can be obtained with MgZnO buffer layers.

Planar optical waveguide in potassium titanyl arsenate formed by oxygen ion implantation at low doses

Monomode, nonleaky planar optical waveguides have been fabricated in x-cut biaxial crystal potassium titanyl arsenate (KTiOAsO4 or KTA) by 3.0 MeV O+ ion implantation at doses from 5×1012 to 1×1014ions∕cm2 at room temperature. The waveguide properties were characterized by the method of prism coupling at 633 nm. Positive changes of both nx and ny refractive indices (corresponding TE and TM polarized light separately) occur in the waveguide region. The propagation loss of the waveguide formed at a dose of 5×1013ions∕cm2 was reduced to 0.66dB∕cm after annealing at 230 °C for 30 minutes. Continuous and homogeneous magnified field pattern of the propagation light in the annealed waveguide was collected and studied by end-coupling method.

Lithium niobate channel waveguide at optical communication wavelength formed by multienergy implantation

Channel waveguides at 1540 nm in X- and Z-cut LiNbO3 are formed by one-step multienergy MeV O2+ implantation. Single perpendicular mode in both planar and channel waveguides is demonstrated. In the ne channel waveguide, double transverse modes are observed because of the large index difference and broad width of the channel. A single transverse mode is obtained in the no channel waveguide. The thickness of the waveguide is less than 2 mum, and the compactness of the waveguide is attributed to the large index difference between the guiding region and the low-index barrier. The mode patterns and the waveguide loss are measured and analyzed. The loss of 0.9 and 0.7 dB/cm are obtained from the no and ne channel waveguides, respectively.

Formation of waveguides in LiNbO3 by 6.0MeV F3+ implantation

6.0MeV F3+ ions are implanted into x-cut LiNbO3 crystals in doses ranging from 3.0×1013to1.0×1015ions∕cm2 at room temperature. Planar waveguide formations are confirmed and dark modes are measured by prism coupling technique with a wavelength of 633nm. TE modes due to both raised extraordinary index and barrier-confined waveguides are demonstrated. The Rutherford backscattering∕channeling technique is used to investigate the damage produced by implantation. The experimental results are analyzed. With a fiber probe technique, the waveguide loss from TE0 mode in sample implanted with the dose of 1.0×1014ions∕cm2 is measured which is about 0.76dB∕cm after annealing.