yrammuS 要概103Rahmat Hidayat104Intan MUCHTADI105Veinardi SuendoDesign of Lasers Medium Based Nd3+ doped Bismuth Borate(Project 2014)Implementation of Accelerated Pollard Rho for Security of Elliptic Curve Cryptography(Project 2014)Development Linearly-Polarized Photoluminescence Technique as An Observation Method Of N-H Tautomerism Effect In Porphyrin Crystals(Project 2014)75Photopumped laser based on rare earth (lanthanides) still becomes an interesting research study, particularly in the development of laser systems utilizing laser diode as its pumping source. The use of laser diode offers some advantages such as more practical and more compact in comparison to the system using conventional discharge lamp. However, the output laser beam from diode laser is smaller in size and lower in intensity in comparison to discharge lamp, therefore it requires laser gain medium with optical characteristics and geometrical shapes different from conventional laser gain mediums. In this research work, we have studied the preparation of Nd3+ doped in Bismuth and Borate glasses as the optical gain medium for that kind of laser system. Those prepared glasses were characterized by absorption and photoluminescence spectroscopy, where Nd3+ doped borate glass exhibits stronger light absorption and emission. The absorption increases with the concentration of Nd3+ ion concentrations, but the photoluminescence is found to be strongest for 1% Nd3+ ion concentration. In order to design the optimum dimension, we have developed also the calculation programs to simulate the optical gain. The programs were built by solving the transition rate equations for steady state condition and employing the finite difference time domain (FDTD) method. Both simulation programs are able to shows the optical gain in a several cm medium length, with a requirement that the emission cross section of the medium should be about 10−19 cm2.For encryption process, in this research we present implementation of arithmetic operation algorithms on polynomial basis. And for security issue, in this research we implement modified Pollard Rho algorithm on ECC over GF (241). As the result, the runtime of Pollard’s Rho algorithm increases exponentially with the increase of the ECC key length. This research also presents the estimated runtime of Pollard Rho attack on ECC over longer bits.In this research, a fast and economical optical measurement system based on polarized photoluminescence will be developed to observe the N-H tautomerism in porphyrin crystals. This measurement system is developed to overcome the requirement of routine characterization of N-H tautomerism in free-base porphyrin synthesis which usually carried out using 1H NMR spectroscopy technique. In spite of 1H NMR spectroscopy is the main characterization technique in study of porphyrin N-H tautomerism, it has several drawbacks which might not suitable for routine characterization purposes, such as high operation cost, very expensive instrument, and slow characterization process. These three factors are very important to consider in case of routine analysis with large number of samples, i.e. in the synthesis of various type porphyrin compounds for dye-sensitized solar cell (DSSC). Moreover, the price of a polarized photoluminescence measurement system is considerably cheap, where it may cost only 1-5% of NMR spectrometer, which makes polarized photoluminesce an interesting optical
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