Search

Locally Er3+-doped noncongruent, Li-deficient Ti:Er:LiNbO3 strip waveguide was fabricated with a technological process in sequence of preparation of Li-deficient LiNbO3 substrate using Li-poor vapor transport equilibration (VTE), Er3+, and Ti4+ diffusion in wet O2. The Li2O content change was evaluated from the measured birefringence. The Ti4+ and Er3+ profile characteristics in the waveguide were studied by secondary ion mass spectrometry. The results show that the VTE and subsequent Er3+ diffusion procedures resulted in totally ∼0.8 mol% Li2O content reduction. The Ti4+ profile follows a sum of two error functions in the width direction and a Gaussian function in the depth direction of waveguide. The Er3+ profile follows also a Gaussian function. At 1130 °C, the Ti4+ surface/depth diffusivity and surface concentration are 8.5 ± 1.3/1.98 ± 0.06 μm2/h and ∼7 mol%, respectively, and the Er3+ diffusivity and surface concentration are (12.8 ± 0.3) × 10−2 μm2/h and ∼0.6 mol%, respectively. [ABSTRACT FROM PUBLISHER]

We have studied thermal effect on filtering feature of electro-optic long period grating (LPG) in Ti-diffused LiNbO3 waveguide, and observed the phenomenon of thermally induced multi-wavelength filtering. At room temperature (20.8 °C), a rejection band due to LPG effect is observed at 1450 nm wavelength regime for a driving voltage of 115 V. As the temperature is increased, the band weakens gradually, and is no longer discernible at 27 °C. Meanwhile, three new dips with similar contrasts and wavelength intervals are resolved at shorter wavelengths 1190, 1265 and 1339 nm. Their contrasts increase with a rise in temperature and have a value of 20 dB at available temperature of 44.5 °C. The positions of these dips change little with the temperature, but red-shift with the increase of driving voltage. These dips are associated with thermally induced multi-mode interference. [ABSTRACT FROM AUTHOR]