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Das, Bikash Kumar
- Growth of ZnO Thin Films on Silicon and Glass Substrate by Pulsed Laser Deposition a Thesis
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Authors
Affiliations
1 Condensed Matter Physics Institute of Physics, Siksha 'O' Anusandhan, Bhubaneswar, IN
1 Condensed Matter Physics Institute of Physics, Siksha 'O' Anusandhan, Bhubaneswar, IN
Source
Journal of Physics & Astronomy, Vol 9, No 7 (2021), Pagination: 1-12Abstract
Thin films find a wide application in developing microelectronic devices, sensors, anti-reflective and protective coatings on advanced equipments, transparent electrodes etc. These make equipments versatile and more efficient. Various techniques are being devised to grow high quality thin films. One such advanced technique is the Pulsed Laser Deposition technique which comes under the category of Physical Vapour Deposition technique. In this technique the material to be deposited i.e. the target, is ablated using laser pulses resulting in the plasma formation. This plasma then interacts with the background gases supplied into the vacuum chamber. Finally it condenses on the object to be coated with the material i.e. the substrate, and nucleates to get deposited as a thin film. PLD is a simple, faster and economical technique. High quality films with desired crystalline structure can be grown using this technique. However a number of factors are involved which determine the film quality like pressure optimization, target composition and form, substrate temperature and laser pulse features. The project deals with deposition of zinc oxide on silicon and quartz substrates by PLD technique and to study the characteristic of the thin film by UV Visible spectroscopy. Zinc Oxide is considered to be a future material due to its multifunctional properties. It crystallizes in two structures viz. Hexagonal wurtzite and Cubic zinc blend. Its high conductivity and low thermal expansion leads to its wide application in ceramics. The striking feature of ZnO is that it is a wide direct band gap semiconductor with a band gap of 3.25eV which corresponds to energy in the UV range. It is a potential material to develop optoelectronic devices that would emit radiations in UV range. Besides the binding energy of excitons is 60 meV. This makes the excitons stable at room temperature (energy equivalent of which is 25 meV) and hence is an essential feature for lasing action. Developing ZnO oxide thin films facilitates research to develop ZnO optoelectronic devices. The project involves the study of the PLD technique and its various aspects like optimization conditions and film growth. A study has been made on the objective behind developing ZnO thin films. The study has inspired me to get involved in developing higher quality thin films for manufacturing optoelectronic devices made up of ZnO.Keywords
Optoelectronic Devices, Stoichiometry, Krypton Fluoride.References
- Jagadish C, Pearton SJ Zinc oxide bulk, thin films and nanostructures: processing, properties, and applications. Biomed Pharmacother. 20025;6(8):365-79.
- Kittel C, McEuen P, McEuen P. Introduction to solid state physics. New York: Wiley; 1996.
- Morintale E, Constantinescu C, Dinescu M. Thin films development by pulsed laser-assisted deposition. Physics AUC. 2010;20(1):43-56.
- Tjossem PJ. Laser Fundamentals by William T. Silfvast. Am. J. Phys. 65:932.
- Laser Fundamentals by William T. Silfvast.
- Jagadish C, Pearton SJ. Zinc oxide bulk, thin films and nanostructures: processing, properties, and applications. Elsevier 2011.
- Azadmanjiri J, Srivastava VK, Kumar P et al. Two-and three-dimensional graphene-based hybrid composites for advanced energy storage and conversion devices. J Mater Chem A. 2018;6(3):702-34.
- Zinc Oxide Bulk, thin films and nanostructures; processing, properties and applications by chennupati jagadish and stephen J. pearton.
- Kittel C. Introduction to solid state physics.
- Sanger L. The early history of Nupedia and Wikipedia: a memoir. Open sources. 2005;(2):307-8.
- Scattering of Perfect Optical Vortex Beams : Physical Unclonable Function
Abstract Views :106 |
PDF Views:1
Authors
Affiliations
1 Department of Physics, Technion-Israel Institute of Technology, Haifa, IL
1 Department of Physics, Technion-Israel Institute of Technology, Haifa, IL
Source
Journal of Physics & Astronomy, Vol 10, No 2 (2022), Pagination: 1-7Abstract
Nowadays, data security has become an important part for anyone connected to the web. Data security ensures that data is getting transmitted securely without any modifications or alterations to the intended receiver. To achieve data security, we have focused on cryptography which helps to protect our information from being stolen or third-party attacks. Encryption techniques demonstrate an excellent deal of data security when implemented in an optical system such as Holography due to the inherent physical properties of light and the precision it demands. Such systems are somehow vulnerable during their digital implementation under various attacks called crypt-analysis due to the predictable nature of security keys used for the encryption. In this work, we are presenting a Physically Unclonable Functions (PUFs) for producing a robust (stable over time) security key for digital encryption systems. More specifically, we have used the correlation functions of scattered perfect optical vortex beams for the generation of keys which can be used for encryption of data. Here, we convert the 2-D correlation function to 1-D key and digitize based on the average value which will be the random sequence of 1s and 0s. In the best of our knowledge, we are reporting this work for the first time. The experiment and simulation results are well matched.Keywords
Cryptography, Encryption, Decryption, PUF, Security, Cipher.References
- Goyal A, Aggarwal S, Jain A. Quantum cryptography and its comparison with classical cryptography: A Review Paper. In 5th IEEE International Conference on Advanced Computing and Communication Technologies. 2011:1-517.
- Mandel L, Wolf E. Optical coherence and quantum optics. Cambridge university press. 1995.
- Kumar P, Fatima A, Nishchal NK. Image encryption using phase-encoded exclusive-OR operations with incoherent illumination. J Optics. 2019;21(6):065701.
- Wang W, Hanson SG, Miyamoto Y. Experimental investigation of local properties and statistics of optical vortices in random wave fields. Phys Rev Lett. 2005;94(10):103902.
- C R Alves, A J Jesus Silva, EJ Fonseca. Opt Lett. 2015:40;2747.
- Goodman JW. Speckle phenomena in optics: theory and applications. Roberts and Company Publishers. 2007.
- Vanitha P, Lal N, Rani A et al. Correlations in scattered perfect optical vortices. J Optics. 2021.
- Ostrovsky AS, Rickenstorff-Parrao C, Arrizón V. Generation of the “perfect” optical vortex using a liquid-crystal spatial light modulator. Optics letters. 2013;38(4):534-6.
- AT Friberg, T Setala. Electromagnetic theory of optical coherence (invited). J Opt Soc Am. 2016:33;2431-42.
- S Liu, C Guo, J T Sheridan, A review of optical image encryption techniques, Opt Laser Technol. 2014:57;327-42.
- Chen W, Javidi B, Chen X. Advances in optical security systems. Adv Opt Photonics. 2014;6(2):120-55.
- Refregier P, Javidi B. Optical image encryption based on input plane and Fourier plane random encoding. Optics letters. 1995;20(7):767-9.
- G Unnikrishnan, J Joseph, K Singh. Optical encryption by double-random phase encoding in the fractional Fourier domain. Opt Lett. 2000:25;887-89.
- G Situ J Zhang. Double random-phase encoding in the Fresnel domain. Opt Lett. 2004:29;1584-86.
- O. Matoba, B. Javidi. Encrypted optical memory system using three-dimensional keys in the Fresnel domain. Opt Lett. 1999:27;762-64.
- H Rubinsztein-Dunlop, A Forbes, MV Berry, et al. Roadmap on structured light. J Opt. 2017:19;013001.
- C Rosales-Guzman, B Ndagano, A Forbes, et al. A review of complex vector light fields and their applications. J Opt. 2018:20;123001.
- A Forbes. Structured light from Lasers. Laser Photon Rev. 2019:13;1900140.
- G Qu, W Yang, Q Song, et al. Reprogrammable meta-hologram for optical encryption. Nat Commun. 2020:11;5484.
- A Trichili, AB Salem, A Dudley, et al. Encoding information using Laguerre Gaussian modes over free space turbulence media. Opt. Lett. 2016:41;3086-89.
- X Fang, H Ren, M Gu. Orbital angular momentum holography for high-security encryption. Nat Photon. 2019:14;102-08.
- Z Qiao, Z Wan, G Xi, et al. Multi-vortex laser enabling spatial and temporal encoding. Photoni X. 2020:1;13.
- Y Zhao, J Wang. High-base vector beam encoding/decoding for visible-light communications. Opt Lett. 2015:40;4843-46.
- G Milione, TA Nguyen, J Leach, et al. Using the nonseparability of vector beams to encode information for optical communication. Opt Lett. 2015:40;4887-4890.
- M Xian, Y Xu, X Ouyang, et al. Segmented cylindrical vector beams for massively-encoded optical data storage. Sci Bull. 2020:65;207279.
- H. Larocque, A. D Errico, MF Ferrer-Garcia, et al. Optical framed knots as information carriers. Nat Commun. 2020:11;5119.