[en] Planar waveguides were formed in LiTaO₃ crystals by using 6.0-MeV C³⁺-ion implantation at room temperature. The prism-coupling method was used to take dark mode measurements at both 633 nm and 1539 nm. The reflectivity calculation method was used to reconstruct the refractive index profile in the waveguide. TRIM'98 (Transport of Ions in Matter) was also used to simulate the damage distribution in the LiTaO₃. Barrier-confined waveguides were found to be formed in LiTaO₃. Possible reasons for the different refractive-index profiles in the LiTaO₃ and the LiNbO₃ waveguides are discussed.

[en] This paper reports the basic results obtained from an investigation of the microstructure of lithium niobate (LiNbO₃) crystals fabricated by using the focused ion beam (FIB) sputtering method. The morphology characterization of the microstructure is explained in terms of scanning electron microscopy observations based on the geometrical integrity, surface smoothness, cross-sectional area, aspect ratio, etc. The optimized micro-fabrication conditions and the sample morphology characterization are presented, and the sputtering rate of Ga ions for a 30-keV energy milling of the LiNbO₃ crystal is calculated, which is lower than the theoretical one gained from 'The Stopping and Range of Ions in Matter' (SRIM) sputtering simulation due to the redeposition effect being enhanced with increasing milling depth.

[en] A ridge waveguide structure was prepared on a z-cut LiNbO₃ crystal wafer by a combined process of ion implantation and precise dicing. The single-crystal LiNbO₃ was implanted at room temperature using 3 MeV oxygen ions at a fluence of 5 × 10¹⁴ ions/cm². After annealing to 200 °C, ridge structures were formed on the wafer surface by precise diamond blade dicing. Two different ridge widths, 8 and 10 μm, were chosen for comparison. The refractive index profile was reconstructed, and the near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. FD-BPM was used to simulate the guided mode profile. Transmission and reflection optical microscopy were used to obtain micro-photograph images of the waveguide structure

[en] We report on MgAl_2O_4 planar waveguides produced using different energies and fluences of C-ion implantation at room temperature. Based on the prism coupling method and end-face coupling measurements, light could propagate in the C-ion-implanted samples. The Raman spectra results indicate that the MgAl_2O_4 crystal lattice was damaged during the multi-energy C implantation process, whereas the absorption spectra were hardly affected by the C-ion implantation in the visible and infrared bands.

[en] We reported a planar waveguide structure on an Nd"3"+:Li_6Y(BO_3)_3 sample fabricated using 6 MeV C ion irradiation at a fluence of 2.5 × 10"1"5 ions/cm"2. Guided modes were detected in the visible and near-infrared wavelength regions. The refractive index profiles were reconstructed based on the effective refractive index functions. The near-field light intensity files in the visible and near-infrared bands were measured using the end-face coupling method with different light sources.

[en] We report the fabrication of a planar optical waveguide in a Ca_0_._4Ba_0_._6Nb_2O_6 crystal by irradiation with 6.0 MeV oxygen ions. We measured the guiding mode by the prism-coupling method at 633 nm and 1539 nm. The near-field intensity distributions were measured by the end-face coupling setup at a wavelength of 633 nm. The reflectivity calculation method (RCM) was used for reconstructing refractive index profiles. SRIM was used to simulate the electronic and nuclear stopping power caused by oxygen ion irradiation, and the finite-difference beam propagation method (FD-BPM) was used to simulate the near-field intensity distributions. Micro-Raman spectra were measured at room temperature in air to study the differences between the substrate and waveguide region

[en] The erbium ions at energy of 400 keV and dose of 5 × 10¹⁵ ions/cm² were implanted into silicon single crystals at room temperature at the angles of 0°, 45° and 60°. The lateral spread of 400 keV erbium ions implanted in silicon sample was measured by the Rutherford backscattering technique. The results show that the measured values were in good agreement with those obtained from the prediction of TRIM'98 (Transport of Ions in Matter) and SRIM2006 (Stopping and Range of Ions in Matter) codes

[en] Ion beam technology has been a popular and established method to modify the optical properties of a large variety of crystal materials. In this study, the influence of C³⁺ ion irradiation at an energy of 6.0 MeV with a fluence of 5.0 × 10¹⁴ ions/cm² on the optical properties, including waveguide and spectral properties, of Ce:Lu₂SiO₅ were investigated. First, the displacement per atom (dpa) and X-ray diffraction (XRD) were used to analyze the change in the lattice structure of the irradiated region. The waveguide properties were studied by the prism coupling and end-facing coupling techniques and discussed in terms of the reflectivity calculation method (RCM). The absorption spectra and Raman spectra were measured to analyze the absorption characteristics and molecular vibration of samples. The photoluminescence spectra before and after irradiation were investigated. The experimental results reveal that the intensity of the emission spectra is enhanced after C³⁺ ion irradiation.

[en] Planar and channel waveguides were fabricated in periodically poled lithium niobate crystals by 6 MeV O-ion implantation. Single-pass second harmonic generation was carried out. A conversion efficiency of 34.5%/(W . cm²) was achieved in the channel waveguide, and 1.11 mW second harmonic light at 492.5 nm was generated. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

[en] Defects in semiconducting transition-metal dichalcogenides (STMDs) are expected to significantly affect the physical properties of bulk material. In this paper, we explore the effect of defects in monolayer tungsten diselenide (WSe₂) modified by ion irradiation. The monolayer WSe₂ on Al₂O₃ was irradiated with a 1.0 MeV C⁺ ion source at fluences of 5.0 × 10¹³ ions/cm² and 5.0 × 10¹⁴ ions/cm². The surface morphology and binding energy before and after carbon-ion irradiation was analyzed using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The Raman spectra were measured in order to study the vibrational and the electronic properties of the material. Red shifting of the $A_1\prime$ and blue shifting of the $E^{\prime }$ modes were observed with monolayer WSe₂ after carbon-ion irradiation. Meanwhile, in the photoluminescence (PL) spectra, we found that the bandgap can be effectively controlled. The change of the photoluminescence peak in monolayer WSe₂ allows potential applications in a range of novel optoelectronic technologies.