Free Essay

Adaptive Optics

In: Science

Submitted By rosalind9
Words 3056
Pages 13

Adaptive optics is a new technology which is being used now a days in ground based telescopes to remove atmospheric tremor and thus provide a clearer and brighter view of stars seen through ground based telescopes. Without using this system, the images obtained through telescopes on earth are seen to be blurred, which is caused by the turbulent mixing of air at different temperatures.

Adaptive optics in effect removes this atmospheric tremor. It brings together the latest in computers, material science, electronic detectors, and digital control in a system that warps and bends a mirror in a telescope to counteract, in real time the atmospheric distortion.

The advance promises to let ground based telescopes reach their fundamental limits of resolution and sensitivity, out performing space based telescopes and ushering in a new era in optical astronomy. Finally, with this technology, it will be possible to see gas-giant type planets in nearby solar systems in our Milky Way galaxy. Although about 100 such planets have been discovered in recent years, all were detected through indirect means, such as the gravitational effects on their parent stars, and none has actually been detected directly.


Adaptive optics refers to optical systems which adapt to compensate for optical effects introduced by the medium between the object and its image. In theory a telescope’s resolving power is directly proportional to the diameter of its primary light gathering lens or mirror. But in practice , images from large telescopes are blurred to a resolution no better than would be seen through a 20 cm aperture with no atmospheric blurring. At scientifically important infrared wavelengths, atmospheric turbulence degrades resolution by at least a factor of 10.

Space telescopes avoid problems with the atmosphere, but they are enormously expensive and the limit on aperture size of telescopes is quite restrictive. The Hubble Space telescope, the world’s largest telescope in orbit , has an aperture of only 2.4 metres, while terrestrial telescopes can have a diameter four times that size.

In order to avoid atmospheric aberration, one can turn to larger telescopes on the ground, which have been equipped with ADAPTIVE OPTICS system. With this setup, the image quality that can be recovered is close to that the telescope would deliver if it were in space. Images obtained from the adaptive optics system on the 6.5 m diameter telescope, called the MMT telescope illustrate the impact.

Two images of a small region in the vicinity of the middle star in Orion’s sword- a cluster of young stars were taken. The images show a close grouping of four stars. In the conventional blurred image, its not possible to make out more than two stars. With the adaptive optics on the other hand, sharpness improves by a factor of 13, making it clear that the fainter star is ,in fact a binary – two stars close together –and a fourth fainter member of the group appears that was previously undetected. [pic]


As light from a distant star reaches the earth, it is made up of plane waves that , in the last microseconds of their journey to the telescope, become badly distorted by atmospheric turbulence. An adaptive optics system reflattens the wave fronts by reflecting the light of a deformable mirror whose shape is changed in real time to introduce an equal but opposite distortion.

The information on how to distort the mirror comes from a wave front sensor, an instrument that measures optical aberration imposed by the atmosphere on light from a star. A fast computer converts the signals coming from the wave front sensor into drive signals for the deformable mirror. The whole cycle operates at a never ending cycle of measurement and correction, at typical speeds of 1000 updates per second.

After the light reflects of the deformable mirror, a beam splitter sends part of the light to a camera that will capture the high resolution image produced by the adaptive optics.

Basic functional diagram



In the early 1970’s the U.S department of defense began supporting an effort to develop a real-time image correction system to obtain sharp pictures of Soviet satellites. The first high resolution images were obtained in 1982. over the next ten years, both military and astronomical communities vigorously advanced the state of the art . A new wavefront sensor and a new deformable mirror that were successfully tested. Later on, pioneering work by the U.S air force showed that an adaptive optics system could operate very efficiently using a laser to create an artificial star in the sky as the wave front reference. This information was a boost to the astronomers, and adaptive optics are now in regular use in large telescopes all over the world.

The European southern observatory, based in Germany operates a very large telescope. It consists of four separate 8-metre telescopes that can be optically linked to form one giant telescope. At present just one of them is fitted with adaptive optics system, feeding a near –infrared camera and low resolution spectrograph, but plans for the eventual addition of adaptive optics to all four.

One other telescope bears special mention: the three meter Shane telescope of the Lick Observatory, on Mt Hamilton. It’s the only telescope that doesn’t need to rely on light from a star to provide information on atmospheric distortion. Instead it uses a laser beam projected into the sky, tuned to 589 nm, the same wavelength as sodium vapour lamps. This laser beam excites a layer of sodium atoms 95 km above the earth’s surface left by meteorites.

These atoms scatter light back to the telescope, creating what looks like a glowing spot in the sky. Currently the lasers needed to do this job are expensive and difficult to maintain, but efforts are being made to change that. The W.M Keck Observatory will soon begin operation with a laser guide star, and as the laser becomes readily available, many other telescope projects will adopt the laser guide star approach to adaptive optics.


Astronomers are mainly interested in the near and mid infrared region. A modern telescope consists of a large concave primary mirror, designed to capture a lot of light, and a smaller, secondary mirror that focuses the light onto a detector. In the infrared, the hardware of adaptive optics consists of an existing telescope, complete with its primary and secondary mirrors, and adds a separate box of optics, including the deformable mirror, to perform the atmospheric compensation.

This approach has two main disadvantages. One is that each additional optical surface beam train absorbs some of the light from the target object in the sky, making the object appear fainter. Also it emits light by virtue of its warmth, introducing thermal noise, further degrading the astronomers, ability to detect faint objects.

In order to avoid this, at the MMT, a separate secondary mirror has been built which does double duty; it acts as a normal secondary by focusing star light onto the high resolution imaging system, but it is also deformable, top act as the adaptive optical wavefront corrector.

Thus starlight coming from the telescope is already fully corrected and focuses down to a high resolution image, with greater intensity and thermal background an order of magnitude lower than what a telescope equipped with conventional adaptive optics could deliver.

But the scientific advantages of wave front correction at the telescope’s secondary faces enormous technical challenges, the most important of them being how to make a piece of glass whose surface could be precisely controlled and shaped to within a few nanometers a thousand times a second.

In order to overcome this, expertise of astronomers was called for. To make the adaptive secondary mirror, two pieces of glass with a very low coefficient of thermal expansion were first ground with matching spherical shapes. They were then bonded together with a 100 micrometre thick later of pitch, a liquid that is very viscous at room temperature.

This arrangement holds the two pieces of glass like a single rigid body as the convex surface is ground down to a membrane just 2 mm thick. The desired optical surface, a hyperboloid was then polished into the membrane with the same technique used for the large primary mirrors. To release the membrane, the whole assembly was baked to 120 degree celsius, melting the pitch and allowing the membrane to slide off the front convex surface of the membrane, coated with aluminium, becomes the deformable mirror.

The second difficulty, controlling the shape of the membrane at high speed and with extremely precision, was later solved. The problem is that the membrane is very floppy, so that in trying to push it around to change its shape rapidly, it rings in hundreds of resonant modes. Unchecked, these resonances would make it possible to control the rapid changes in the shape of the mirror. but by placing the membrane just 40 micrometre away from a second, rigid piece of called the shape reference plate, it was discovered that the thin layer of air between them become so viscous that all the resonances are damped out.

In the fully assembled mirror, the membrane’s shape is controlled by 336 voice-coil actuators, like miniature loud speakers. They couple to 336 rare-earth magnets glued to the back of the membrane. The separation between the copper coils and the magnets is 0.2 mm. A current through each coil generates a variable magnetic field, which exerts a force on the corresponding permanent magnet and moves the glass membrane.

Unique to this deformable mirror are capacitive position sensors that measure the mirror’s local position. The capacitors are chromium rings deposited on the front surface of the reference plate around each of the 336 actuators. The capacitance between each chromium ring and an aluminiium coating on the back of the deformable mirror across the 40 micrometre air gap is about 65 pF. A square wave voltage applied across the capacitors allows them to be read at 40 kHz, giving a measure of the local position of the membrane with respect to the rigid reference plate, accurate to 3 nm.

In the normal orientation when installed in the telescope, the flexible membrane is at the bottom. Above that is rigid reference plate, 50 nm thick, pierced by 336 holes through which poke the actuators. The coils of the actuators are mounted on the ends of 10 cm long aluminium fingers that conduct heat to an aluminium cold plate, two machined pieces glued and bolted together.

Cooling fluid circulates through grooves milled into the lower plates. The fluid is a mixture of distilled water and methanol. This solution won’t freeze even at cold temperatures. Above the cold plate are three electronic units containing 168 DSPs. Each DSP is responsible for controlling two actuators, reading the capacitive sensors and updating the drive currents in the coils to keep the mirror in right shape. This makes it resistive to vibrations, wind buffeting and changes in the direction of gravity. It has been shown that the MMT adaptive optics system holds its shape to an astonishing 10nm against winds at speeds of about 50 kmph.

Thus with the difficulties in building an adaptive secondary mirror overcome, we will be able to see in detail a mechanism by which stars of varying masses are distributed through the galaxy.


Canceling distortion in the MMT’s adaptive optics system, light from the primary mirror, distorted by the atmosphere, reflects from the adaptive secondary mirror that is deformed to correct for the distortion. A beam splitter shunts some light from this mirror to a wavefront sensor. The sensor’s output goes to an array of digital signal processors in a control computer, which calculates how much and where to deform the mirror to compensate for the atmospheric distortion. The corrected light passes through a lens that focuses it into a high-resolution image.


Perhaps the most exciting scientific program to benefit from the new approach to adaptive optics will be to look at Jupiter like planets orbiting other stars. Roughly 100 such stars have been found out through observations of the effects on the motion of their parent stars, but none has ever be seen by direct imaging. It happens because they are extraordinarily faint and to compound the problem, they are right next to something that is enormously brighter.

We can learn about the environments in which the planets form. Measurements of the planet’s brightness at different wavelengths will tell us about the planet’s temperature and chemical composition and whether the system has conditions to support life. Observations in the thermal infrared region of the spectrum will be particularly valuable because many simple organic molecules like methane emit strongly there. We can also exercise many of the observational techniques and new technologies required to eventually find and study earth-like planets.

The big challenge here is to distinguish a planet’s light from that of its parent star. In the visible range, where planets shine by reflecting starlight, contrast ratios between a planet and its star can be extremely large.

Younger giant planets, less than a billion years old or so, still retain much of the heat created by their evolution out of the primeval matter from which their solar systems were formed, and radiate strongly in the thermal infrared. But most planetary systems, like our own are much older. They will have cooled and will no longer glow in the thermal infrared as they once did.

A further complication occurs when trying to capture an image of the stellar system at the telescope. Regions of the image close to the star, where its planets may be found, are swamped by a halo of starlight scattered by earth’s atmosphere. The halo adds photon noise orders of magnitude greater than the tiny planetary signal. To hope of finding the planet, we must rely on adaptive optics to suppress the halo as much as possible. The very low thermal background radiation coming from the MMT adaptive optics system provides a crucial advantage by reducing the photon noise against which the planet must be seen.

The stellar halo can also be suppressed still further through destructive interference, using a technique called nulling interferometry. In this procedure, the two images from two telescopes are overlapped exactly and in such a way that at the location of the star, the crests in the light waves from one telescope fall on the troughs of the waves from the other, canceling each other out. Thus a dark image is formed where, before, the bright stellar image was found.

The principle of conservation of energy requires that the starlight not be destroyed, and indeed it appears at a second output of the nulling interferometer. It is removed, though, in the crucial region closest to the star we would expect to look for planets. Planetary images will therefore be seen with greatly improved contrast.


As we continue to develop this program, further improvements in our instrumentation will allow us to see fainter objects. The next major step will be the completion of the Large Binocular telescope, combining two 8.4 m primary mirrors on a single mount , each equipped with its own secondary mirror. The corrected light from the two halves of the telescope will then be brought together in the centre in a new nulling interferometer which is being built.

Predictions of the instrument’s sensitivity show that we can expect direct detection of several planets already known to exist like Ursae Majoris, and v Andromedae. Many others are likely to be discovered for the first time because of the instrument’s ability to explore a much greater region of space around each star than is possible with today’s indirect detection methods.


• Only infrared is currently practical. • Small isoplanatic patch (area that needs research)

Because the isoplanatic patch for the atmosphere is so small, only a tiny fraction of the sky will be near suitably bright stars that can serve as reference. But this has now been overcome now by using lasers to excite sodium atoms in the atmosphere, producing an artificial star that can be placed near any target of interest.


There are many substantial technological challenges in AO. Among them are the development of fast, very low-noise detectors in order to be able to correct with fainter reference stars; high-power reliable & easy to operate sodium lasers; very fast processors exceeding 109 to 1010 operations per second; deformable mirrors with bandwidths of several kilohertz and with thousands of actuators, and large secondary adaptive mirrors. The latter are especially interesting at thermal wavelengths, where any additional mirror raises the already huge thermal background seen by the instruments. There are AO systems in the Infrared routinely achieving near diffraction-limited images and spectroscopic data cubes on large telescopes up to the present generation of 8-10 m diameter. Significant corrections have been obtained in the visible in exceptionally good seeing conditions Many recent astronomical discoveries can be directly attributed to new optical observation capabilities. With the new generation of Very Large Telescopes entering into operation, the role of AO systems is extremely important. With this capability, their huge light-gathering along with the ability to resolve small details, both spatially and spectrally, has the potential to bring major advances in ground-based astronomy in the new decade. Further down the line, the giant optical telescopes of the future will rely on advanced AO systems for basically all their observations; they will have to be incorporated right at the start of the projects.


• IEEE Spectrum December 2003 • • •


The turbulent mixing of air at different temperatures continually changes the speed and direction of starlight as it passes through the atmosphere. It limits the resolution of a telescope and makes the images seen through it, blurred. Adaptive optics is a new technology which in effect removes this atmospheric tremor and helps the astronomers see the images through earth based telescopes more brightly.




10. References

adaptive optics…...

Similar Documents

Premium Essay

Optic Glicomas

...Optic Gliomas In Neurofibromatosis Nickeya Wimberly, Natalie Willis, Rima Patel, Dan Cary Galen School Of Nursing   Critique an assigned nursing research article using established criteria A. Identify if the article has a review of literature. The article we have chosen is filled withother links that allows us to get more information from other sources that backs up the clinical trial that is being tested. A chart shown at the end of the article also shows a breakdown of the data that was collected during the trial to back up the conclusion the researches came to. B. Determine the purpose of the article. The purpose of the article was to determine the relationship between optic gliomas and neurofibromatosis. Optic gliomas- are regarded as benign tumors of the central nervous system originating from glial tissue. These tumors are frequently asymptomatic and are among the seven diagnostic criteria of Neurofibromatosis. Possible complications of the gliomas are decreased vision and blindness. Regular eye exams may allow early diagnosis of these tumors before they cause symptoms. C. Identify the population used in the study. The population of the study consisted of 85 children 51 with neurofibromatosis and 32 without any symptoms or signs of neurofibromatosis. D. Identify the methods used in the study. The methods used in the study were radiologic such as MRI and CT scans, and ophthalmologic examinations. E. Determine the findings of the study. The study was......

Words: 273 - Pages: 2

Free Essay

Fiber Optics vs Led

...Fiber optic light sources must be able to turn on and off millions to billions of times per second while projecting a nearly microscopic beam of light into an optical fiber. Both Light Emitting Diodes and Laser transmitters are considered to be semiconductor light sources. However, they differ greatly in output patterns. Forward biased LEDs generate light when positive voltage is applied to the “p” region and negative voltage is applied to the “n” region of the diode. Random photons are emitted at the junction where the “p” and “n” regions meet once a current is passed through the LED. The photons that are emitted are out of phase and not launched in the same direction. This is called incoherent light. Only a small percentage of this light is actually coupled into the optical fiber since incoherent light is difficult to focus. There are two types of LEDs, surface emitting and edge emitting. Surface emitting LEDs are formed from a single semiconductor material in the “pn” junction. Because of this, incoherent photons radiate from all points of the junction. Edge emitting LEDs are formed from similar materials with different refractive indexes. These indexes are used to guide the light and create a directional output. Light is emitted though an etched opening in the diode. Laser sources also have a “p” and “n” region but contain the emitted photons using an optical cavity and reflecting mirrors on each end of the diode. One mirror is only partially reflective......

Words: 563 - Pages: 3

Free Essay

Fibet Optics

...Reliable, Consistent, Quality 1-877-320-3143 Reliable, Consistent, Quality Welcome To Fibertronics Inc. Reliability, consistency, and quality is what we put behind every Fiber optic patch cable assembly we manufacture. Fibertronics Inc. specializes in fiber optic Communication products. Our cable assemblies are manufactured in our own facility. This makes all cables completely customizable. Beginning manufacturing in 2009, we are known for our quick quotes and very fast turn around service. Your Best fiber optic cable manufacturer for the excellent products, quality, competitive prices, fast delivery and good service. We not only offer OEM fiber optic assemblies to some of the worlds leading companies in this industry, but we also cooperate with many other companies from all over the world and support these partners to win in the market. We are a professionally staffed fiber optic company and distribution company. Located in Melbourne Florida USA. All fiber optic patch cables are guaranteed to meet and exceed the customers expectations. 1-877-320-3143 2 1-877-320-3143 Reliable, Consistent, Quality Assemblies Single Mode 10 Gig Om3/Om4 Multimode Custom Assemblies Specialty Mode Conditioning Node/Drop Cables Couplers Broadcast/Military 4 4 7 8 CALL 10 11 12 12,13 46 Tools & Consumables 34 Tool kits Stripping & cutting Cable Splitters Scribes Crimpers Ovens Solvents......

Words: 12157 - Pages: 49

Premium Essay

Adaptive Systems as I can, trying desperately to throw off the lampreys that seem to feed off my pain, and suck and suck and suck on my flesh! I swim so hard that I nearly exhaust myself, slowing down, sinking down, while those little, circle shaped rows of teeth nibble on my sensitive dorsal regions, sending arcs of strangely exhilarating electric pain up and down my sleek, aerodynamic frame. After approximately another week of this training I was not only capable of overcoming the discomfort of the eppendorf tube impinging on the delicate bulb of my glans, I was even finding somewhat arousing. Truth be told, it was actually difficult for me to return to what most of you would consider the “normal” procedure. (Some of you are probably asking, “But adaptive, why didn’t you use the established technique for acquiring sperm samples from men who are either dead, uncooperative, severely neurologically impaired, suffering from a catastrophic vertebral injury, or are actually horses? That technique of course being Electroejaculation (EEG), which involves the rectal insertion of an electrical probe that looks something like an electric hair-curler, followed by the application of increasing electric current until the probe either induces ejaculation or heats itself to the point that it threatens to inflict first-degree burns on the entirety of the anal cavity. [pic] To answer your question, I want to be clear: I assure you that the reason I didn’t employ the obviously appropriate method had......

Words: 27507 - Pages: 111

Premium Essay

Introduction of Fiber Optic

...Broadcast technologies. edu Guide An educational resource published by Communications Specialties, Inc.. Introduction to Fiber Optics The equipment, tools and cabling that comprise a fiber optic link, how they work and their advantages over traditional copper. edu Guide Communications Specialties, Inc. is committed to increased education and knowledge in the Pro A/V and Broadcast industries. We hope that you enjoy reading – and learning! – with our eduGuide series of educational resources. For additional information on these and other industry related technologies, please visit us at today! ©2009 Communications Specialties, Inc. All Rights Reserved. Specifications, claims or other product information contained in this document are subject to change without notice. This document may not be reproduced, in whole or in part, without the express written consent of Communications Specialties, Inc., Fiberlink, Pure Digital Fiberlink, the starburst logo, Scan Do and Deuce are registered trademarks of Communications Specialties, Inc. CSI and the triangle designs are trademarks of Communications Specialties, Inc. October 8, 2009 Table of Contents A Brief Introduction ............................................................................................................ 2 Advantages of Fiber Optic Systems .............................................................................. 3 Optical Transmitters......

Words: 5977 - Pages: 24

Free Essay

Adaptive Traffic Control System

...Adaptive Traffic Control System Performance measure against which our proposed policy to be tested is green time utilization. This performance measure is estimated by measuring the green time during which vehicles are served for an instance of a given phase and then dividing by the total length of the green time instance (i.e. minimum and maximum green time) The supporting data for green time utilization are as follows: * Allocated minimum and maximum green time * vehicle departure times * Saturation headway These data can be retrieved from the Signal control data and stop line detector. Our objective is to maintain ideal state as long as possible if control system deviates from this ideal state to (over-utilization) or (under-utilization) then by using adaptive control strategy system will take actions by changing existing policy. Objective: max.8≤Ugfk<1 Subject to constraints: g minfk≤gfk≤g maxfk (1) f=AFgfk≤C (2) Here, Ugf= Average time taken by vehiclesAvailable time Ugf=number of departures in phase f× hsat{gmin, gmax} Ugminf= number of departures in phase f× hsat{gmin}, Ugmaxf= number of departures in phase f× hsat{gmax} So, theoretically the green time utilization should follow following condition to be remain in......

Words: 1648 - Pages: 7

Premium Essay

Optics Lab

...Optics Materials: * Optics bench * Optics kit, including a lens/mirror mount * Convex lens of known focal length * Concave mirror of known focal length * Light source/candle * Screen * Meter stick/metric ruler * Two polarized films * Prism * Laser pointer * Protractor * Graph paper * Electromagnetic spectrum chart Materials for Exploring Further: * Plane mirror * Ripple tank, with sheet of plastic or glass that fits on part of the bottom of the tank, and objects that can be used as boundaries to obstruct the pathway of waves * Wave-motion rope * Tuning-fork kit * Stroboscope * Resonance-tube kit In this lab, you will investigate the relationship between the focal lengths of a mirror and lens and the type of image that is generated. Procedure 

Part 1: Image from a Lens 

1. Place the light source, convex lens, and screen on the optics bench as shown in figure 1. Start with the light source at a distance greater than 2ƒ from the lens. 
 Figure 1 2. Measure the height of the light source, or "object" (ho), and record it in data table 1. Also measure and record the distance between the lens and the light source (do) in the data table. Using the lens equation and the given focal length, calculate the distance from the lens to the image (di) and the height of the image (hi): and . Record your calculations in......

Words: 3049 - Pages: 13

Free Essay

Fiber Optics

...EXECUTIVE SUMMARY You may ask yourself what is needed for a new building and what are the codes that must be followed in order to have a building nice and free of hazards. Well to start here are the new building requirements for the following materials: patch cables, cat 6 cables, fiber optic multi-mode, cable trays, Cisco- WS-C3750 G24PS-S 24 Ports, laser printer, vertical runs, computers, Cisco border router, server run a and server run b. The following codes must be in play to ensure the building or work space is safe for everyone. 1. American National Standards Institute (ANSI). 2. Electronic Industries Alliance (EIA) 3. Telecommunications Industry Association (TIA) 4. Insulated Cable Engineers Association (ICEA) 5. National Fire Protection Association (NFPA) 6. National Electrical Manufacturers Association (NEMA) 7. Federal Communication Commission (FCC) 8. Underwriters Laboratories (UL) 9. International Organization for Standardization (ISO) 10. International Electrotechnical Commission (IEC) 11. Institute of Electrical and Electronic Engineers (IEEE) 12. National Institute of Standards and Technology (NIST) 13. International Telecommunications Union (ITU) 14. CSA International (CSA) 15. IP/MPLS Forum (ATM Forum) 16. European Telecommunications Standards Institute (ETSI) 17. Building Industry Consulting Services International (BICSI) 18. Occupational Safety and Health Administration (OSHA) 19. ANSI/TIA-568-C Cabling Standard The......

Words: 1121 - Pages: 5

Premium Essay

Pm Adaptive

...I would recommend Adaptive project management methodology. The two aspects that make this method appropriate for the potential clients are; “Iterative decision-making or making choices based on learning from the outcomes of decisions previously taken and strategic flexibility or avoidance of irreversible decisions” (Virine, 2008). Adaptive PM will enable the organization to follow a structured PM system but will also provide the ability to change according to the organizations strategic plans and ongoing decision-making process. The organization is withholding the nature of the project; this would guide the project management to a structure that will be supportive the strategic impact, ability to refine the project based on needs, and lessons learned, and flexibility required for this project and the organization. Project management uses different methods to structure the project plan. Project management methodology allow the project manager and the organization to understand and see the project roadmap, milestones, timeline, risks, and manage desired outcome. Some of the methodologies utilized in project management are adaptive, Crystal Methods, Waterfall, and lean. As an example, the Waterfall method would not fit the potential client as its model does not allow change; it is fixed to methods, timelines and specified tasks (Tutorials Point). When analyzing which method is appropriate for the project, the desired outcome and strategic objects need to be clearly......

Words: 373 - Pages: 2

Free Essay

Adaptive Leadership

...Impacting Learning Through Adaptive Leadership Siemens Corporation is a multinational electronics and industrial engineering firm that focuses in the areas of industry, energy, and healthcare. Our company provides data storage for Siemens and I went to undergrad with one of its employees, Sasha Patel. In this paper, two employees of the Siemens IT department were interviewed to evaluate their perception of Siemens’s loyalty to its values in both communication and practice. As the interview responses indicate, while Siemens holds a strong commitment to leading in innovation, it must continually upgrade its communications approach to spread its vision and mission to all employees of the organization. In order to determine whether Siemens communicates its mission and values effectively through all levels of the organization, both a leader and subordinate were interviewed. The first interviewee of the Siemens Healthcare IT division was George Stephen, an IT manager who has worked for Siemens Corporation for three years. The first series of interview questions considered how the mission and vision statements of the organization were communicated within the organization. As Stephen noted, “all employees are provided with an overview of the company history and values during their orientation. Management is considered to set its goals by considering how those goals are aligned with company values. When a team of consultants is dispatched to meet with representatives......

Words: 950 - Pages: 4

Free Essay

Pinhole Optics

...VANDERBILT STUDENT VOLUNTEERS FOR SCIENCE Pinhole Optics Fall 2005 Purpose: To learn how a pinhole affects how we see things using a pinhole magnifier and pinhole camera. I. Introduction A pinhole is exactly what it sounds like, a small hole made with a pin. Experiments with pinholes are useful because the way light travels through the hole is very similar to the way light travels through the eye. The pupil, the small black area in the center of the eye, acts similarly to the pinhole. It is small compared to the big things in the world you are looking at. The retina, the back part of the eye where special cells sense light and send signals to the brain via nerves, acts similarly to the screen in the camera. II. Pinhole Magnifier Materials: 20 Pinhole magnifiers (index card with a small hole punched in aluminum foil inserts) 20 Pieces of newspaper (in an envelope) A pinhole in an index card can act like a magnifying glass, helping your eye focus on an object that is very close to you. However, by limiting the amount of light that reaches your eye from the object, the pinhole also makes the object appear dimmer. Pass out a pinhole magnifier (index cards with a small hole punched in aluminum foil inserts) and piece of newspaper to each student. Use the pinhole magnifier to look at the text of the newspaper and notice that it appears larger. Now try making a pinhole magnifier with your fingers like......

Words: 1974 - Pages: 8

Premium Essay

Fiber Optics

...Fibre Optics A relatively new technology with vast potential importance, fibre optics, is the channelled transmission of light through hair-thin glass fibres. The clear advantages of fibre optics are too often obscured by concerns that may have been valid during the pioneering days of fibre, but that have since been answered by technical advances. Fibre is fragile An optical fibre has greater tensile strength than copper or steel fibres of the same diameter. It is flexible, bends easily, and resists most corrosive elements that attack copper cable. Optical cables can withstand pulling forces of more than 150 pounds. Fibre is hard to work with This myth derives from the early days of fibre optic connectors. Early connectors where difficult to apply; they came with many small parts that could tax even the nimble fingered. They needed epoxy, curing, cleaving and polishing. On top of that, the technologies of epoxy, curing, cleaving and polishing were still evolving. Today, connectors have fewer parts, the procedures for termination are well understood, and the craftsperson is aided by polishing machines and curing ovens to make the job faster and easier. Even better, epoxyless connectors eliminate the need for the messy and time- consuming application of epoxy. Polishing is an increasingly simple, straightforward process. Pre-terminated cable assemblies also speed installation and reduce a once (but no longer) labour-intensive......

Words: 2158 - Pages: 9

Free Essay

Nanoscale Optics

...Traditional and new simulation techniques for nanoscale optics and photonics a I. Tsukerman*a, F. Čajkoa, A.P. Sokolovb Department of Electrical & Computer Engineering, The University of Akron, OH 44325-3904, USA b Department of Polymer Science, The University of Akron, OH 44325-3909, USA ABSTRACT Several classes of computational methods are available for computer simulation of electromagnetic wave propagation and scattering at optical frequencies: Discrete Dipole Approximation, the T-matrix − Extended Boundary Condition methods, the Multiple Multipole Method, Finite Difference (FD) and Finite Element (FE) methods in the time and frequency domain, and others. The paper briefly reviews the relative advantages and disadvantages of these simulation tools and contributes to the development of FD methods. One powerful tool – FE analysis − is applied to optimization of plasmon-enhanced AFM tips in apertureless near-field optical microscopy. Another tool is a new FD calculus of “Flexible Local Approximation MEthods” (FLAME). In this calculus, any desirable local approximations (e.g. scalar and vector spherical harmonics, Bessel functions, plane waves, etc.) are seamlessly incorporated into FD schemes. The notorious ‘staircase’ effect for slanted and curved boundaries on a Cartesian grid is in many cases eliminated – not because the boundary is approximated geometrically on a fine grid but because the solution is approximated algebraically by suitable basis functions.......

Words: 5791 - Pages: 24

Free Essay

Fiber Optics

...History of Fiber Optics The idea of using light waves for communication can be traced as far back as 1880 when Alexander Graham Bell invented the “photo-phone” shortly after he invented the telephone in 1876. In this remarkable experiment, speech was transmitted by modulating a light beam, which traveled through air to the receiver. The flexible reflecting diaphragm (which could be activated by sound) was illuminated by sunlight. The reflected light was received by a parabolic reflector placed at a distance of about 200 m. The parabolic reflector concentrated the light on a photo-conducting selenium cell, which formed a part of a circuit with a battery and a receiving earphone. Sound waves present in the vicinity of the diaphragm vibrated the diaphragm, which led to a consequent variation of the light reflected by the diaphragm. The variation of the light falling on the selenium cell changed the electrical conductivity of the cell, which in turn changed the current in the electrical circuit. This changing current reproduced the sound on the earphone. Fiber Optic Technology Fiber Optic is a technology that uses glass as thin as a human hair to transmit data from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves. It is......

Words: 2001 - Pages: 9

Free Essay

Fiber Optics

...Fiber is Basis of Info Highway Table of Contents Title Page1 Table of contents2 Article Review…………………………………………………………………………………………………………………………………..3-4 Companies Review....................................................................................................................................5-7 Works Cited8 The article “Fiber is Basis of Info Highway”; written by: Mathew Ingram for the Globe and Mail; is about the race to cover the globe with fiber optic cable. The author talks about corporate buyouts and huge company mergers to compete in the fiber optic Industry. I found the article intriguing to read and understand why companies are competing in the field and the rate at which there competing. I’ll be going over some of the mergers and buyout in a bit as well as mentioning some of the big players in this fiber optic game. Every few days there seems to be a new fiber related deal going on. Just to note a few of the bigger ones; JDS Uniphase merged with E-Tek Dynamics in a $15 billion (US) deal. JDS is a product from a merger a year previous with JDS Fitel and Uniphase; is already one of the largest fiber-equipment companies, and well on its way to becoming what analysts call the Intel of fiber (referring to Intel’s dominance of the computer chip market). Nortel Networking is another company throwing large sums of money around in the fiber world, paying $3.2 billion (US) for Qtera Systems who’s technology boosts the carrying power of the fiber. Nortel’s......

Words: 1117 - Pages: 5