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Islam R.-U.,National Institute of Lasers and Optronics | Khosa A.H.,COMSATS Institute of Information Technology | Saif F.,Quaid-i-Azam University | Bergou J.A.,CUNY - Hunter College
Quantum Information Processing | Year: 2013

We present an experimentally feasible method, based on currently available cavity QED technology, to generate n-partite linear cluster and graph states in external degree of freedom of atoms. The scheme is based on first tagging n two-level atoms with the respective cavity fields in momentum space. Later on an effective Ising interaction between such tagged atoms, realized through consecutive resonant and dispersive interactions of auxiliary atoms with the remanent cavity fields, can generate the desired atomic momenta states. The procedure is completed when the auxiliary atoms after passing through Ramsey zones are detected in either of their internal states. We also briefly explain the generation of weighted graph states in the atomic external degree of freedom. © 2012 Springer Science+Business Media, LLC. Source

Aman H.,National Institute of Lasers and Optronics
Laser Physics | Year: 2012

In this paper the construction of a mechanically Q-switched diode side pumped Nd:YAG laser system is described. It consists of a 50 cm long plane-plane resonator Q-switched with a combination of a rotating prism and a mirror. With an optical to optical efficiency of 25% Q-switched pulses (@1064) of 48 mJ and 8 ns are obtained at a rep-rate of 30 Hz with an output in near TEMoo mode. At a peak power of 6 MW the M 2 value is found to be 1.92. The laser is frequency doubled and then tested on a 50 μm thick tantalum foil which results in circular holes of diameter 13 μm in it. © Pleiades Publishing, Ltd., 2012. Source

Aman H.,National Institute of Lasers and Optronics
Journal of Russian Laser Research | Year: 2013

We describe the design and operation of a diode-pumped compact and efficient Nd:YAB laser operating at 1338 nm. We use a passive Q-switch V:YAG crystal to achieve 1 mJ Q-switched pulses at the laser output. The laser elaborated provides an average power of 1.5 W in the CW regime and 1 W in Qswitched mode with an optical efficiency of 15 and 10%, respectively. A 65 mm plano-concave cavity is formed with an output in the TEM00 mode. At a pulse width of 15 ns, the achieved peak power is 66 kW. © 2013 Springer Science+Business Media New York. Source

Ali Z.,Sungkyunkwan University | Ali Z.,National Institute of Lasers and Optronics | Shakir I.,Sungkyunkwan University | Kang D.J.,Sungkyunkwan University
Journal of Materials Chemistry A | Year: 2014

Photoelectrochemical cells have existed for decades. However, the poor efficiency of such devices is still problematic because of trade-offs between different materials properties used for photoelectrochemical reactions. Here we report a novel photoanode architecture consisting of CdS/CdSe co-sensitized sea urchin-shaped ZnO/TiO2-based nano/micro hybrid heterostructures that simultaneously offer better light scattering over the entire visible frequency domain, better separation of photo-generated charge carriers, significantly improved light absorption that extends over a broad visible spectrum, and better transport of electrons through a highly connected network of conducting ZnO nanowires than existing architectures. Use of the synthesized structures as photoanodes in a photoelectrochemical cell yielded a photocurrent density as high as 11.8 mA cm-2 with a remarkable photo-conversion efficiency of 6.4%. This journal is © the Partner Organisations 2014. Source

Khoptyar D.,Lund University | Subash A.A.,Lund University | Johansson S.,Lund University | Saleem M.,National Institute of Lasers and Optronics | And 3 more authors.
Optics Express | Year: 2013

We present extended spectroscopic analysis of pharmaceutical tablets in the close near infrared spectral range performed using broadband photon time-of-flight (PTOF) absorption and scattering spectra measurements. We show that the absorption spectra can be used to perform evaluation of the chemical composition of pharmaceutical tablets without need for chemo-metric calibration. The spectroscopic analysis was performed using an advanced PTOF spectrometer operating in the 650 to 1400 nm spectral range. By employing temporal stabilization of the system we achieve the high precision of 0.5% required to evaluate the concentration of tablet ingredients. In order to further illustrate the performance of the system, we present the first ever reported broadband evaluation of absorption and scattering spectra from pure and doped Spectralon®. © 2013 Optical Society of America. Source

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