Conclusion and scope for further work

Transcription

1 203 Conclusion and scope for further work Chapter 7 Conclusion and scope for further work 7.1 Conclusion Before presenting the conclusions, for the sake of easy reference, the objectives of the present work are reproduced below as stated in Chapter l. Security holograms with fixed data content are used worldwide. The aim of the present work is to develop methods for producing machine-readable holograms with variable data content for additional security and secure product tracking. Spatial light modulator is essential for incorporating variable data content and in the market it is highly expensive. So, cost effective spatial light modulator is needed for light modulation of variable data to be incorporatedin each hologram.

2 204 Conclusion and scope for further work Holographic data storage systems demonstrated earlier was quite expensive and meant for high density data storage on disc shaped materials. The present work as envisaged involves design, development and implementation of a cost effective holographic real time data storage system to record variable data microholograms. The system has to produce microholograms on Photopolymer strips and the recorded holograms are to be read subsequently to authenticate and identify the product on which the microhologram is affixed. Consequently, the present research work had the following objectives: 1) To design and develop cost effective electro-optic Spatial Light Modulators (SLM) for laser beam modulation. 2) To design and develop holographic variable data storage system for recording microholograms on real time Photopolymer material HoloMer-6A. 3) To design and develop a Photopolymer material transport and control mechanism for continuous production of machine-readable security holograms with variable data pages. 4) To reconstruct the variable data pages for authenticating and reading the product information, by processing the holographic data captured and input to a PC. Based on the scope of work and the research work done, the following major conclusions and findings are drawn: Three cost effective electro-optic spatial light modulators were developed and implemented. They are having different

3 205 Conclusion and scope for further work specifications and are applicable to different system requirements. The LCD-SLM is very compact and is strongly recommended for the design ofportable and costeffective holographic data storage systems. A holographic variable data storage system for recording variable data microholograms on real time Photopolymer material was designed, developed and implemented. The data storage system developed is very cost effective due to the use ofthe low cost SLM developed as part ofthe R&D work. Photopolymer material transport and control system was designed, developed and implemented for the continuous production of machine-readable security holograms. The details are described in chapter 5. Real time recording was done since the new Photopolymer material doesn't require any processing. Each microhologram was illuminated with reference beam and the reconstructed data pages were processed in a personal computer and the originality of data were verified. Data pages were given in encoded form for recording microholograms and after reconstruction, decoding and verification were done to prove the originality and to ensure security.

4 The PhowpolYl11\.T material transpurt and control mechanism for the,-'l)ntinulllis pwdl:cticn or m'll'hine readable holograms is a newer one, ~inc\.' it is b~ls\.'d l1j1 cost \.'ire,'live SLl\l dc\'l:loped by the ill\\.'stigator and,lise) li1c recl)["lling nwterj~d is llolomer (,A. a very new Photopolymer l1l~lll'l"ial the pruposed sl)lutions are entirely different l"rom existing solutions, The existing solutions arc for recording millions ol" data pages hok)graphically on a disc sh~lped material. The device called Holographic Versatile Disc (HVD) is about to come to the market. lnphase technologies. U,S.A. demonstrated 300GB disc in the Yl'ar 2007, The material transport and control mechanism incorporated in it is not rcvcaled to the public. The company is aiming to commercialize HVI) with storage capacity upto 1.6Tbytes \\ith a transfer rate of 120Mbytes/sccond. The dri\'e mechanism incorporated can be quite complex and e\en costliest. In the thesis work. the holographic data storage technique is ~lpplied for producing machiile readable variable data microholograms on Photopolymer material. The purpose is to produce security holograms \-vith variable data content in a cost effective way. For that the investigator designed and developed a material transport and control mechanism which is X-Y translational. The variable data content offers additional security and the originality of each hologram can be verified.

5 206 Conclusion and scope for further work 7.2 Scope for further work Chapters 4 to 6 describe the experimental work conducted so far by the investigator. There are various avenues in which further research can be conducted based on the work reported. One such experiment is the multiplexed recording of microholograms with two SLMs for encoding data into both the beams [60]. It is the wish of the investigator that in future security holograms with encrypted and encoded data pages and reconstruction using encoded reference waves will become the major research area in the field of holographic security. This area is having high potential to become developed and will emerge as a major area in the long run. Research can be done to store high volume of data holographically in book like manner. Secure storage can be done by using matched data maskso that only authorised persons can read the content. Research can be done in the field of Integrated Optics to develop miniaturized optical devices of high functionality on a common Photopolymer substrate. This field is far behind its electronic counterpart but more work can be done to develop more and more complex integrated optical devices. Research can be done to put waveguides, modulators, switches and other optical functions onto various substrates. Thin film and micro-fabrication technologies can be adopted to realize optical counterparts of integrated electronics for signal generation, modulation, switching, multiplexing and processing.

6 207 Conclusion and scope for further work Research work on development of all optical computers need effective storage and secure authentication. This is a binary digital computer, which uses photons as information carriers instead of electrons. In a binary computer, storage elements capable of representing two stable states are needed and are a good field of research. Optical Character Recognition (OCR) is an area of research in pattern recognition, artificial intelligence and machine vision. Academic research is going on and the focus on OCR is now shifted to implementation of proven techniques. OCR and digital character recognition can coincide in a number of applications. An important field with high potential of research is Optical Neural Network. An optical neural network is a physical implementation of artificial neural network with optical components. Hopfield neural network and Kohonen Self-organizing map are already implemented as optical neural networks with liquid crystals. All of the artificial neural networks can be implemented as optical neural networks in the long run. It is the hope of the investigator that further work can be done in any of the above field as a continuation ofpresent work.