Waveguides In Nd Research Articles

Optical channel waveguides by proton and carbon implantation in Nd:YAG crystals

In this work the formation of optical channel waveguides in Nd:YAG crystals by either proton or carbon implantation is reported. The channel waveguides were obtained by a single implantation process through an electroformed mask of nickel-cobalt alloy. Experimental measurements of the optical properties of these waveguides are presented.

Optical waveguides formed in Nd:YVO4 crystals by C2+ implantation

This work reports the formation of planar and channel waveguides in Nd:YVO4 by carbon implantation, using doses as low as 5 × 1014 ions/cm2. The analysis includes refractive index profiles, propagation losses and spectroscopic properties. The results indicate that there is an index convergence, the ordinary index increases while the extraordinary index decreases. The spectroscopic studies show that emission bands coming from the 4F3/2 level are not altered by the ion beam process, shedding light on the potential of carbon implanted waveguides for laser integrated devices.

Optical waveguides in Nd:YVO4 crystals by multi-implants with protons and helium ions

This work reports the formation of planar waveguides by proton and helium implantation in Nd:YVO4. Double and triple implants were realised using energies between 0.4MeV and 1.75MeV and doses around 1016ions/cm2, thus generating wide barriers; in particular a double waveguide was generated with a triple implantation. The analysis includes refractive index profiles, spectroscopic properties and near field imaging.

Optical channel waveguides in Nd:YVO4 crystal produced by O+ ion implantation

In this letter, we report on optical channel waveguides in Nd:YVO4 crystals produced by photographic masking and following direct O+ ion implantation at 3.0MeV. Annealing treatments of the samples are performed to improve the waveguide stability and to reduce losses. An increase of the ordinary refractive index induced by the implantation is believed to be responsible for waveguide formation. Quasi-TM guided modes are observed, while no quasi-TE ones are detected. The optical damping coefficients are of 0.43, 0.63, and 0.54cm−1 for channel waveguides with widths of 4, 5, and 6μm, respectively. The result of modal analysis is in agreement with the experimental data.

Analysis of ion implanted waveguides formed on Nd:YVO4 crystals

This work reports, for the first time to our knowledge, the formation of planar waveguides in Nd:YVO4 by either carbon or proton implantation. The waveguides are characterised using the dark mode method and by spectroscopic studies, indicating that there is a reduction of the refractive index at the end of the ion track. Particularly, carbon implantation generates a considerable variation in the guiding region. It is shown that the waveguiding structure preserves the spectroscopic properties of the Nd3+ ions, thus maintaining the crystal quality.

Luminescence of Nd3+ in proton or helium-implanted channel waveguides in Nd:YAG crystals

Abstract Positive index changes were induced by ion implantation in neodymium doped YAG, in strip areas written by means of a specific slit-based set up, allowing efficient channel waveguiding. Thick waveguides (10 μm) were in particular formed by using H + ions. Very similar neodymium IR emissions to the one of the bulk were recorded around 1.06 μm, for an excitation at 810 nm, in both kind of waveguides.

Optical waveguides in Nd:YAG by proton implantation

Proton implantation has been used to produce optical waveguides in Nd:YAG. Two- and four-implant guides have been characterised by the dark mode method and by spectroscopic studies. A very small index enhancement was obtained as it was expected in this material as well as other insulators. It is shown that the luminescence properties of the Nd ions are not significantly altered by the ion beam process, thus maintaining the crystal quality in the guiding region.

Property study of Si + -ion-implanted Nd:YVO 4 waveguides

Planar waveguides were formed in Nd:YVO4 crystals by 3.0-MeV Si+-ion implantation at doses of 1×1013–1.5×1015 ions/cm2 at room temperature. The effective refractive indices of the waveguide propagation modes were measured by using a prism-coupling method. It was found that the number of the propagation modes is dependent on the doses for the waveguides in Nd:YVO4. The atom displacement in the near-surface region (about 2 μm beneath the surface) of the Nd:YVO4 crystal induced by the implantation was simulated by using the TRIM 98 (transport and range of ions in matter) code. The possible reasons for the waveguide formation are discussed in a primary way.

MeV Ni + ion-implanted planar waveguide in Nd:YVO 4 crystal

The 2.8 MeV Ni + ion-implanted planar optical waveguide in Nd:YVO 4 crystal is reported. The prism coupling method is used to measure the dark modes of the Nd:YVO 4 waveguide. It is found that the effective refractive indices of all the extraordinary modes are lower than that of the substrate ( n e), while the effective indices of the first three ordinary modes have a positive change compared with that of the substrate ( n o). Both n e and n o profiles in the waveguide are reconstructed by reflectivity calculation method (RCM).

Ion-implanted waveguides in Nd 3+-doped silicate glass and Er 3+/Yb 3+ co-doped phosphate glass

The data are presented on the waveguides formation in the Nd 3+-doped silicate glass and Er 3+/Yb 3+ co-doped phosphate glass by the implantations of He + or Si + ions, respectively. The prism-coupling method is used to measure the effective refractive indices of the waveguide dark modes. The refractive index profiles of the waveguides are reconstructed by using the reflectivity calculation method (RCM) and a comparison of such profiles among the different waveguides has been made. The reasons for the formation of the present waveguides are analyzed in a primary way.

Improvements of ion implanted waveguides in Nd:YAG and LiNbO 3 using pulsed laser anneals

Pulsed laser annealing has been used to modify the surface and refractive index profiles of ion implanted waveguides formed in Nd:YAG and LiNbO 3 crystals. Major improvements are seen in the niobate guides where losses are reduced, better refractive index confinement occurs in the garnet. The improvements depend on laser pulse power and the number of pulses, since prolonged laser treatments can introduce surface damage in the niobate, and/or emphasise the problems of surface instability on the garnet. The improvements in waveguide loss and surface quality are encouraging and optimisation of the laser conditions should enhance the waveguide performances.

MeV copper and nickel ion implanted waveguides in Nd:NaY(WO 4) 2 crystal

The first MeV copper and nickel ion implanted waveguides in Nd:NaY(WO 4) 2 are reported. The planar optical waveguides were formed in this crystal by 2.8 MeV Cu + or Ni + ion implantation with doses of 1–3×10 15 ions/cm 2 at room temperature, respectively. The dark modes were observed by prism coupling method. The reflectivity calculation method was used to analyze the refractive index profiles of the waveguides.

Ion-Implanted Planar Optical Waveguides in Nd:MgO:LiNbO3

Nd:MgO:LiNbO3 is a laser material. Planar optical waveguides in Nd:MgO:LiNbO3 were formed by He+ implantation to doses of 1.4 × 1016 and 1.5 × 1016 ions/cm2 at energies of 2.8 and 2.5 MeV, respectively, and dark modes were observed by the prism coupling method. The effect of MeV He ion implantation on the lattice order of the crystals in the guiding regions of the waveguides was analyzed by the Rutherford backscattering/channeling technique. The refractive index profiles are all calculated and fitted by using WKB method and PIPR method, respectively. The fluorescence spectrum of the sample has been measured.

Characterization of ion implanted waveguides in Nd:YAG

Ion implantation into Nd:YAG has been used to produce waveguides which are capable of supporting laser action. The refractive index profiles have been characterized as a function of ion dose and energy, implant temperature, and subsequent thermal annealing. Transmission losses down to 1.2 dB/cm have been obtained in the optimized waveguides. There is a temperature independent index enhancement of ∼0.15% in the electronic stopping (guiding) region. The nuclear collision damage is temperature dependent, and shows an initial index increase (∼0.3% for dose 1 × 1016 ions/cm2), but a subsequent decrease of up to several percent, which forms an optical barrier, as has been observed in many other crystalline materials. The best mode confinement and attenuation is obtained by utilizing the low dose nuclear index enhancement produced by several equally spaced implants (multiple energy) to give a broad well with Δn∼0.25%. Several unusual features of the profiles are reported and discussed.

Ion implanted Nd:YAG waveguide lasers

A detailed description of the use of ion implantation to create optical waveguides in laser crystals is given. Calculated mode profiles and lasing thresholds are shown to be in good agreement with experimental results in a monolithic planar waveguide Nd:YAG laser. The first fabrication and characterization of ion implanted channel waveguides in Nd:YAG is also reported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>