Optics Today- An Overview

OPTICS TODAY- AN OVERVIEW. Ratnam Challa Optics, like a field of science, is well into it's 2nd millennium of life; yet in spite of its age, it remains remarkably vigorous and youthful. Optics is an enabling science and is an important component of modern, high technological, societies and economies. According to Australian Optical Society Report, March, 1994, Most in studies and industry, optics is a primary growth region of modern science and technology that shows no signs of abating within the foreseeable future. Prediction is very difficult, spoke about NIELS BOHR, mostly regarding the future.

3 decades ago optical computing was a thriving region of studies that offered the prospect of computers many faster than those available at the time. Of course, computers are indeed many faster currently than they were 20 years ago, but they can be still not optical. However, there have been higher than enough developments in other regions of optics, most pure and applied, over this period to compensate for that specific disappointment. Little of these advances were planned or predicted, but many were completely unexpected PETER RODGERS, Physics world' Editor, April 2005. Optics is one regarding the growth regions of modern physics and engineering.

Like a result, optics finds applications in almost every walk of life in our society. Optical devices are crucial components in many sectors of industry. The development of our modern technological lifestyle is becoming increasingly linked to developments within the field of optics. This encompasses regions that are well known in traditionaloptics:. optical fabrics glasses, crystals, thin film technology.

optical components lenses, mirrors, gratings,. photometry light measurement, colour definition. solar collectors and concentrators. Optical processes cameras, telescopes, microscopes, photocopiers etc. lighting and display systems.

Conventional optical components are already present in many devices and instruments, which are in everyday use in our society. The ability to measure, and to compute with velocity and accuracy are the hallmark requirements of today's physical and exact sciences. Since its introduction within the late 1950's, the digital computer has furthered the computational abilities of person beyond the wildest dreams. Currently computer is used in almost every field of studies in optics, not to speak fewer about any other field. The fields of optics that have particularly profited from the use of computers are two Lens creation and Thin Film creation 3 Image Processing and Evaluation 4 Atmospheric Optics 5 Space Optics six Remote Sensing and in more recent times seven Medicinal Optics.

IMPORTANCE OF RESEARCH IN MODERN OPTICS. There is a considerable quality, breadth and depth in optics research, and within the non-residential applications of studies in optics. For any place Optics is an appropriate sector in terms of its contribution to wealth generation and employment and its little environmental impact AUSTRALIAN OPTICAL SOCIETY REPORT, March, 1994. The new fields of Modern Optics encompass growing regions which are at the forefront of current scientific research, for example Lasers, Fibre optics, Photonics, Optical Computing, Atom Optics, Fourier Optics etc. More importantly, the applications of modern optics increasingly underpin our corporate and economic well being, and are an important component of modern, high technology industry.

lasers in medicine cancer surgery, laser angioplasty, eye surgery. optical communications mass details transfer, optical switching. imaging and sensing bar code readers, laser alignment tools. optical data storage compact discs, digital cameras. precision measurement laser rangers and gyroscopes, interferometers.

holography data storage, structural testing, security devices. materials processing laser annealing, drilling and cutting. History of Development of Modern Optics. Since the early 1960`s, it has gradually grow to accepted that an up to date academic training in optics should with a heavy exposure to concepts of Fourier Analysis and Linear processes theory. During the middle regarding the 20thcentury, different events and discoveries have provided new life, life and richness to field of optics.

The highest many important events have been. two The introduction regarding the concepts and tools of Fourier Analysis and communication theory into optics 1940-1960. 3 The discovery and successful realization regarding the LASER within the late 1950 `s. 4 The origin regarding the field of non linear optics in 1960`s. 5 The infusion of statistical concepts and methods of analysis into the field of optics.

six Computers have distant accelerated the pace of development within the field of optics throughout the entire century. A realization regarding the utility of Fourier methods within the analysis of optical processes arose rather spontaneously within the late 1930's when a many studies workers began to advocate the use of sinusoidal test patterns for system evaluation. Many regarding the initial stimulus was supplied by a French scientist P. DUFFIEUX, whose work culminated within the publication of a book, in 1946, on the use of Fourier methods in optics. Unfortunately this pamphlet has not ever been translated into English and is not widely available.

Within the United States, many regarding the interest in these topics was stimulated by an electrical engineer named OTTO SCHADE, who very successfully employed the methods of linear processes theory and communication theory within the analysis and improvement of television camera lenses. Subsequently the foundations of Fourier optics were in fact laid considerably earlier than 1940, particularly within the works of Ernst Abbe 1840-1905 and God Rayleigh 1842- 1919 GOODMAN, 1968. In the late 19th century LORD RAYLEIGH had solved many fundamental problems in acoustics and optics. The discovery regarding the quantized nature of light had dramatically increased the need for statistical interpretation of Quantum Mechanics in optics, which was first introduced by MAX BORN GOODMAN 1984. In 1954 EMIL WOLF introduced an elegant and broad framework for considering the coherence properties of waves, which laid foundation for multiple important statistical problems in 0ptics that should be treated in a uniform way.

An function of special mention is the classical theory of light detection pioneered by L. MANDEL which tied together in a comparatively simple way, the knowledge regarding the fluctuations of classical wave quantities fields, intensities and fluctuations associated with the interaction of light and matter. A student position course in Physics, today, encounters optics in an entirely deterministic framework. Physical quantities are represented by mathematical functions that are neither completely specified in advance or assumed to be precisely measurable. These physical quantities are subjected to well-defined transformations that modify their shape in perfectly predictable manner.

For example, the path of a monochromatic light wave with a known complex field distribution at a sure distance distant from the screen shall be calculated precisely by creating use of the well-established diffraction formulae of wave optics. Thirty years ago, the enormous impact of lasers on modern optics and technology should not havebeen predicted. Even now, the full section of likely applications afforded by lasers has yet to be realized. There exists also signs that other fields in modern optics, for example atom optics where atoms are controlled with light within the similar to method as conventional optics controls light with reason release similar potential for new technological applications. Optics is no detailed an isolated branch of physics.

There is a best deal of transformation within the read of Optics over the decades with the use of computers. Optics has developed to its present status by borrowing mathematical concepts from diverse fields for example communication engineering, electronics, nuclear physics, etc. It is the wave nature of light that creates this link possible. CURRENT RESEARCH AREAS IN OPTICS:. University studies in optics is spread throughout applied and fundamental areas.

These things have been coarsely classified into regions and are briefly described below. a Optical Fibres and Photonics. One regarding the primary advances in this technology is the development of facilities for the design, fabrication and testing of specific optical fibres. This activity includes the studies and development of next generation components and devices within optical switches, fibre lasers and fibre amplifiers. These devices are of importance to advancement of photonics.

Photonic devices and circuits are being developed for application to very high bit rate optical communication processes and networks within regional and metropolitan region networks for delivery of pay television etc. Other studies is being undertaken into nonlinear optical fabrics and devices with applications to all optical switching. This work is at the leading edge of technology for the future. be Lasers and Applications. Lasers ranging from semiconductor, solid state and CO2 processes operating within the infrared- to- metal vapour regions and rare gas lasers operating within the visible and ultra violet are being researched and developed.

The application of laser technology is prevalent, particularly in non-destructive testing and diagnostics, high precision machining of polymers creating use of ultraviolet lasers. The read of man-made plasmas and hypersonic gas flows creating use of laser diagnostics, medicinal diagnostics employing lasers, and holography are just some regarding the studies topics undertaken in universities in which laser technology is directly applied. c Conventional Optics. The field of conventional optics plays a role of ever increasing importance. Diverse things for example microscopy, imaging, optometry, solar collectors and astronomy are ongoing things in different studies institutes throughout the world.

A large different variations of specialist microscopes are currently below development in a many active studies groups which are likely to be in departments of physiology and anatomy as well as in departments of physics. Many hospitals are also very active as there is promise, creating use of advanced imaging techniques, for developing methods for the early detection of diseases for example glaucoma. Astronomy shall also be dependent on high quality optics as highlighted by the custom precision optics, lasers and quantum imaging devices used by the Sydney University Stellar Interferometer. The development of suitable optical components is essential to advancement of solar life technology that has the potential to deliver cost effective and efficient electricity and also to grow to an export earner. AUSTRALIAN OPTICAL SOCIETY REPORT, March, 1994.

The read of vision spans scientific disciplines from mathematics to physiology. Understanding the processes of pattern recognition and visual processing shall have implications in problems associated with mechanical system vision for example section sensing and measurement of optic flow. There is growing studies interest and activity in this area, that is evolving as an important component in high technology sector throughout the world. e Atomic and Molecular Physics and Quantum Optics. This predominately fundamental region of studies is important to optics in 3 ways.

Firstly, most modern methods of investigating processes in atomic and molecular physics involve the use of state regarding the art lasers together with high quality optics. Secondly, primary advances in modern optics have emanated from this area. For example, the discovery of optical bistability in atomic sodium was the precursor to field of photonics. Atomic physics gave the earth the laser and more recently, squeezed states. The list shall be continued.

Studies in atomic and molecular physics and quantum optics is an region of strength in institutes of advanced research. f Particle and Atom Optics. Over the final ten years there was explosive growth of worldwide interest within the optics of massive particles for example atoms and neutrons. This region is of considerable importance as it not only assists fundamental studies in fabrics science and astronomy but also underpins the regions of medicinal imaging. Many regarding the experimental techniques in x-ray optics, consequently common in principle with other regions of optics, present a special set of challenges.

JEAN BAPTISTE JOSEPH FOURIER March 21, 1768 Shall 16, 1830 was a French mathematician and physicist who is greatest known for initiating the investigation of Fourier series and their applications to problems of heat flow. The Fourier Transform is named in his honor. The mathematical technique of Fourier transforms in association with correlation and convolution, when applied to optics resulted within the subject of Fourier transform optics or Fourier Optics, that is an important branch of Modern Optics. The foundation to Fourier Optics was laid within the works of Ernest Abbe and God Rayleigh GOODMAN, 1988 and Michelson STEWARD, 1983. The importance and the art regarding the Fourier transform in optics was briefly but beautifully summarized by FRANCON 1974.

According to him the wave aspect of light is the fundamental reason for the important role played by Fourier transform within the field of optics. In fact, the Fourier transform returns in like an organic tool for representation of all vibrational phenomena in physics. It translates the principle of Huygens and enables the read of diffraction phenomena. It translates the formation of images of extended objects and brings within the notion of transfer function. It describes the degree of spatial coherence in terms of source geometry and distant more, the degree of temporal coherence in terms of source spectrum.

It plays a fundamental role in spatial filtering, character recognition and image processing. Finally, within the website of Interference spectroscopy, it relates the intensity distribution within the source to spectral distribution of source energy. Thus, the use of Fourier analysis, justified by the wave aspects of light, presents for optics, the possibilities which are distant from possessing being exhausted LAKSHMANA RAO, 1994. The statistical properties of light play an important role in determining the outcome of most optical experiments. A description in terms of sure 2nd order averages known as coherence functions is entirely adequate for predicting experimental outcomes.

The origins regarding the modern concept of coherence shall be located within the scientific literature regarding the 19th and early 20thcenturies. Particularly noteworthy early contributions were created by E. VON LAUE 1906, 1907, 1907, 1909, 1910, 1915, 1915? M. VANCITTERT, 1934, 1939? F. ZERNIKE 1938, 1948 and others.

The next developments of primary importance are located within the work of H. BLANC-LAPIERRE and DUMONTET 1954, E. WOLF 1953, 1954, 1954. The historical evolution of concept of coherence is presented with an extensive bibliography by L. Emil Wolf is a living legend within the field of physical optics.

An icon within the earth of optics, Emil Wolf laid the foundations of contemporary physical optics by documenting the concept of spatial coherence prior to lasers were introduced. This powerful concept has influenced many regions of optical science and engineering, Tribute to Emil Wolf: Science and Engineering Legacy of Physical Optics, Editor s? TOMASZ P. JANNSON Publication Date: Dec 2004. Since its conception, the medicinal field was searching for better ways to understand the person body. Today, the optical field is finding new ways to assist in this process.

two of those ways is through electromagnetic radiation imaging. On the cutting edge of this field is the g- ray coded aperture imaging. What is Coded Aperture Imaging?. The coded aperture imaging is an indirect method of imaging in which the conventional pinhole or multi-channel collimator is replaced by a plate containing a coded hole pattern or opening. A spot gamma ray source shall cast a shadow of this hole pattern on a detector and this shadow is the coded image regarding the spot source, which shall also be called the point-spread function regarding the coded aperture.

A source distribution two-dimensional or three-dimensional is encoded like a superposition of many such shadows. This encoded pattern on the detector plane is called the shadowgram regarding the object distribution of intensity. The creation regarding the coded aperture is chosen to facilitate the image reconstruction or decoding process sequential to make sure that a faithful reproduction regarding the object or the source distribution on the image plane. The decoding shall be accomplished by a many methods- most optically and electronically. Coded Aperture Imaging is a technique originally developed for X-ray astronomy by MERTZ 1961 and YOUNG 1963 where typical imaging problems are characterized by far-field geometry and an object created of spot sources distributed over a mainly dark background.

These conditions provide, respectively, the basis of artifact-free and high Signal-to-Noise Ratio SNR imaging. In a report titled Computer aided Zone Plate 3-D Imaging: Theory, Software and Implementation sponsored by Laser Plasma Division, Centre for Advanced Technology, Department of Atomic Energy, Govt. of India, June, 2003, the authors G. PANT have reported that Coded Imaging CI Techniques are being many preferred to conventional Imaging Techniques mostly for imaging sources of brief wavelength radiations. The CI Techniques have created significant contribution within the following fields:.

a X-ray Astronomy: [ Diek 1968? Young 1963 ]. b Nuclear medicine: [Barrett 1972? Barrett et al 1973? Rogers et al 1973 ]. c Nuclear engineering [Rose et al 1975, Rose 1976 ]. d Inertial Confinement Fusion [Ceglio and Coleman 1977, Ceglio and Larson 1980? Bruno et al 1979 ]. BARRETT, who is at present Regents Professor in Optical Sciences Centre within the University of Arizona, USA A, has contributed an enormous wealth to field of Coded Aperture Imaging Technique and has a huge many USA Patents to his credit.

He has a huge team of researchers who have themselves published very useful work in this field of research. Holography is a technique that allows the light scattered from an object to be recorded and later reconstructed such that it appears as if the object is within the similar to position relative to recording moderate as it was when recorded. The image changes as the position and orientation regarding the viewing system changes in exactly the similar to method as if the object were still present, thus creating the recorded image hologram appear Three-Dimensional. The technique of holography should possibly be used to optically store, retrieve, and process information. Holographic data storage is a technique that can save details at high density inside crystals or photopolymers.

The ability to save huge amounts of details in some kind of press is of best importance, as many electronic products incorporate storage devices. As current storage techniques for example Blue- Ray Disc reach the limit of likely data density due to diffraction-limited volume regarding the writing beams, holographic storage has the potential to grow to the next generation of well-known storage media. The advantage of this kind of data storage is that the volume regarding the recording press is used instead of just the surface. In 2005, businesses for example Opt ware and Maxell have produced a 120mm disc that uses a holographic layer to save data to a potential 3. 9 TB terabyte, which they plan to market below the name Holographic Versatile Disc.

Another company, In Phase Technologies, is developing a competing format. Security holograms are very difficult to forge due to the fact that they can be replicated from a master hologram which requires expensive, specialized and technologically advanced equipment. They can be used widely in many currencies for example the Brazilian Real 20 note, British Pound six or 10 or 20 notes, Estonian Croon 25 or 50 or 100 or 500 notes, Canadian Dollar six or 10 or 20 or 50 or 100 notes, Euro six or 10 or 20 or 50 or 100 or 200 or 500 notes, Southern Korean Won 5000 or 10000 or 50000 notes, Japanese Yen 5000 or 10000 notes, etc. They can be also used in credit and bank cards as well as Passports, ID cards, books, DVDs and hobbies equipment. This is only a brief exposition on the ever growing importance of optics within the different fields of life.

The earth of optics is distant reaching and a thorough read is beyond the scope of this article. However, anyone interested in a career in Optics can definitely get an system of this ever growing branch of Physics. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx--------xxxxxxxxxxxxxxxxxxxxxxxxxxxxx. AUSTRALIAN OPTICAL SOCIETY REPORT, March, 1994. BORN and WOLF, 1959, Principles of Optics, 1st edition, p.

Y BORN and WOLF, 1965, Principles of Optics, p. Pergamon Press, Oxford. , 1984, In Principles of optics, Pergamon Press, Oxford, SixthEdition, p. 1970 , Principles of Optics. 333,396,398,424,436,438,462,469 and amp;524.

, 1984, in Zone plate coded imaging; theory and applications, in Progress in Optics- XXI, Ed. by Elsevier Science publishers, B. , Aug 1968, Scatter-Hole cameras for X-ray and Gamma-rays, Astrophysical J. 1984, Contemporary Optics, MacMillan India,Ltd. , 1984, In Statistical Optics.

Peter Wiley and amp; Sons, New York. , 1988, In Introduction of Fourier Optics, Re-Issue, Mcgraw-Hill Publ. 1,101, 103, 19, 17, 131. 1968 Introduction to Fourier Optics McGraw- Hill,USA P. 1,17,83,101,103,139 and amp;148.

D Thesis: Studies on Resolution of 3 unequally. bright object points by apodised annular optical processes in partially coherentillumination. D Thesis: FOURIER ANALYTICAL INVESTIGATIONS ON THE PERFORMANCE OFMULTIPLE - ANNULI CODED APERTURES IN MULTIPLEXED TOMOGRAPHY.