G.U.L. Nagy

Experimental setup for studying guiding of proton microbeam

We present the design and construction of our experimental setup for studying the transmission of proton microbeam through a single, cylindrical shape, macroscopic insulating capillary. The intensity as a function of time, the energy distribution as a function of the transmission and the deflection of the transmitted particles can be measured with the new setup.

Recent progress in ion beam fabrication of integrated optical elements

Planar optical waveguides and Bragg gratings were designed and written in various optical crystals with medium energy ion implantation. Some examples of the fabricated integrated optical elements are presented in this article: Planar optical waveguides fabricated in Er: LiNbO3 crystal by irradiation with 5 MeV N3+ ions, and Bragg gratings fabricated by multi-energy implantation into a silicon substrate with N+ ions in the 800 keV - 3.5 MeV energy range. The SRIM code was used for planning the optical elements. The ion implanted optical elements were tested by spectroscopic ellipsometry and visible and infrared reflectometry. The results show that the proposed fabrication methods can produce integrated optical elements of adequate parameters.

The use of ion beam techniques for the fabrication of integrated optical elements

Active and passive optical waveguides are fundamental elements in modern telecommunications systems. A great number of optical crystals and glasses were identified and are used as good optoelectronic materials. However, fabrication of waveguides in some of those materials remains still a challenging task due to their susceptibility to mechanical or chemical damages during processing. Ion beam has been used for such purposes, along with other emerging techniques, like direct pulsed laser writing. Passive and active planar and channel optical waveguides, and optical Bragg gratings were fabricated in various glasses (like Er: TeO2-WO3 glass) and undoped and doped crystals, Bi4Ge3O12, Bi12GeO20) using masked or unmasked macrobeams or microbeams of light and medium-sized ions (C, N, O) in the 1.5 - 11 MeV energy range. Functionality of the optical elements was tested by m-line spectroscopy and end fire coupling technique. Structural changes in the implanted samples were studied by various optical microscopic techniques, spectroscopic ellipsometry, Rutherford backscattering and microscopic Raman spectroscopy. The results show that it is possible to produce integrated optical elements of unique properties using ion beam techniques.

Guiding of 1 MeV proton microbeam through a tapered glass capillary

The guiding of 1 MeV proton microbeam passing through a tapered-shape macroscopic insulator capillary was investigated. The intensity of the transmitted beam and the energy distribution of the transmitted particles were measured. We found that significant fraction of the beam can pass through the capillary without any significant energy loss indicating that the guiding electric field built up inside the capillary.

Can the ions be guided with MeV/amu energies? The case of the 1 MeV proton microbeam

The transmission of 1MeV proton microbeam through aTeflon microcapillary was studied. Using the suitable combination of the capillary temperature and beam intensity we identified three different regions in the transmission as a function of time. In the third region stable guided transmission was obtained where the dominant contribution of the transmitted protons did not suffer energy loss.

Proton microbeam transmission between flat plates

The transmission of 1 MeV proton microbeam passing through between two parallel flat plates was investigated. During the measurements the surface of the plates was parallel to the beam axis. The energy and deflection of the beam were measured as a function of the sample position relative to the beam axis. We found significant differences in the proton transmission for metallic and insulator plates.