All optical switching in henna thin film
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All optical switching in henna thin film Fryad Z. Henari • Khalil E. Jasim
Received: 29 October 2012 / Accepted: 21 March 2013 / Published online: 3 April 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract The optical nonlinearity in henna (Lawson (2- hydroxyl-1,4 naphthoquinone) film was utilized to demonstrate all optical switching. The nonlinear absorption of the henna film was calculated by measuring the transmission of the laser beam (k = 488 nm) as a function of incident light intensities. The observed nonlinear absorption is attributed to a two-photon absorption process. The pump and probe technique was used to demonstrate all optical switching. The switching characteristics can be utilized to generate all-optical logic gates such as simple inverter switches (NOT) NOR, AND NAND logic functions.
There has been considerable interest in searching for new materials that exhibit optical nonlinear properties. In general, the nonlinear optical effects can be used for applications such as optical bistability, optical limiting, all-optical switching and logic devices [1–6]. Most of the conventional all-optical devices are based on the light intensity induced refractive index changes and absorption changes. Many materials such as photo refractive materials [7], Buckminster-fullerenes [8–10], fluoride glasses [11] liquid crystals [12] have been investigated for these applications. Logic gates are used to design digital circuits. Most logic
F. Z. Henari (&) Department of Basic Medical Sciences, Royal College of Surgeons in Ireland, Medical University of Bahrain, PO Box 15503, Adliya, Kingdom of Bahrain e-mail: [email protected]; [email protected] K. E. Jasim Department of Physics, College of Science, University of Bahrain, PO Box 32038, Isa Town, Kingdom of Bahrain
gates (switches) have two inputs and one output, often referred as conditions low (0) or high (1), represented by different positive/negative voltage levels. All-optical switches are highly important due to high speed, parallel processing and more band width. Previously henna dye extracts of different concentrations have been used to demonstrate for the sensitization of nanocrystalline Titanium (TiO2) solar cells [13, 14] and for the nonlinear properties at different wavelengths using z scan technique [15]. Henna was chosen for these applications among other dyes of plant origin, because it is widely available, easy to extract and also its cultural values. In this work, the nonlinear absorption of the henna film was determined by measuring the transmission of the light as a function of the incident light intensities. The observed nonlinear absorption ascribed by a two-photon absorption process. This work also demonstrates how the nonlinear absorption can be utilized to generate all-optical logic gates such as simple invertors switches (NOT gate), OR, NOR, AND and NAND logic gate functions. These functions are demonstrated using the pump and probe technique. To our knowledge the henna has not been considered previously for such optical switching
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