We live in a world bathed in light.  We see with light, plants draw energy from light, and light is at the core of technologies from computing to surgical techniques. 

Most research on optical computing today is based on increasing the efficiency of data transfer using light while minimising energy losses during conversion. Photonic computing utilises an all together different "processor architecture" as compared to today's SoCs (System on Chip), for carrying out the same processes efficiently. Optical Transport Network a rather new addition to this vast subject has further bridged the gap between imagination and reality by offering great data transfer speeds which were not possible via the conventional manner. 

Although Optical computing is still a field under development it promises a bright future with immense possibilities.

Photons does not have the response limitations of electrons so make the process faster. It does not need insulators which make the product cheap and light. It can send different photon signal streams simultaneously using different color frequencies, thus allowing multiple operations. The optical computers promises a processing speed to 100,000 times faster than the current models.

But building a optical computer will not be easy due to the lack in availability of raw materials which can be mass produced. Another challenge is level of accuracy of the optical computers which is between 8 to 11 bits which is quite high.

So we can expect the optical computers to be a reality in future only but in the near term hybrid computers can be possible which makes use both the conventional and optical computing.

Photolithography is a process used in microfabrication to pattern parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate. A series of chemical treatments then either engraves the exposure pattern into, or enables deposition of a new material in the desired pattern upon, the material underneath the photo resist.

For a better picture have a look at this video

https://www.youtube.com/watch?v=zFnJQjcnhGQ

Advantages of optical lithography

• Quick, parallel process • Complex shapes

whereas electron beam lithography is

• Slow (no parallel) • Not wide area (<0.01 mm2)

For transmission of data in any computational architecture we require efficient and dedicated channels. We have almost attained the highest possible speeds with electron based transmissions, however the scope for development in the optical based solution to data transfer is quite vast.

https://www.youtube.com/watch?v=PQXl-atcBsg

The video above provides a good comparison of the two modes and also focusses on research in this field. Photonic computing seems to be a viable replacement once stable, to our current desktops and notebooks.

However the question is, is it possible to scale down this amazing technology to the size of a smartphone's SoC (Microprocessor/System on Chip)?

Today certain mobile SoCs are as powerful as an Ultrabook running Windows OS. For example: Apple's A9 chip on the Iphone 6s. The A9 chip developed by Apple has a performance equivalent to a Intel Core i5 Haswell processor.

http://bgr.com/2015/09/23/iphone-6s-galaxy-s6-note-5-android/

This article link shows how companies like Apple have worked upon optimization of chips with the software and hardware to provide desktop class performance on mobile devices.

So to me it seems pretty safe to guess that scaling down photonic computing to mobile devices is possible.

One of the possible solutions in my view, to accommodate such heavy technology on a 14nm chip is to make the entire casing of a chip out of a single slab of optical material. This in turn help us in reducing the energy losses associated with photon movements. The feasibility still needs to be tested, but yes it is a possibility.

Lasers found their first use in the 1970s in local grocery stores, in the product scanner. The next major accomplishment for laser technology was the CD player. Today, uses span from hospitals to battlefields, to electronics, to factories.

Laser technology is one of the few areas which finds application in a wide variety of streams. Laser technology has revolutionised many areas.

• In medicine: surgical treatment, vision treatment, kidney stone treatment, dentistry, hair removal, skin treatment, tattoo removal, etc.
• In the military: missile guidance, radar replacement, target guidance, etc.
• In electronics: CDs, DVDs, laser printers, holograms, barcode scanners, etc.
• Factories: cutting, welding, heating materials, etc.

Surger Research by Glenn Edwards and colleagues at Vanderbilt University's FEL Center in 1994 found that soft tissues including skin, cornea, and brain tissue could be cut, or ablated, using infrared FEL wavelengths around 6.45 micrometres with minimal collateral damage to adjacent tissue. This led to surgeries on humans, the first ever using a free-electron laser. Starting in 1999, Copeland and Konrad performed three surgeries in which they resected meningioma brain tumors. Beginning in 2000, Joos and Mawn performed five surgeries that cut a window in the sheath of the optic nerve, to test the efficacy for optic nerve sheath fenestration. These eight surgeries produced results consistent with the standard of care and with the added benefit of minimal collateral damage. A review of FELs for medical uses is given in the 1st edition of Tunable Laser Applications.    Fat removal

Several small, clinical lasers tunable in the 6 to 7 micrometre range with pulse structure and energy to give minimal collateral damage in soft tissue were created.^{[citation need} At Vanderbilt, there exists a Raman shifted system pumped by an Alexandrite laser.^[23]

Rox Anderson proposed the medical application of the free-electron laser in melting fats without harming the overlying skin.^[24] At infrared wavelengths, water in tissue was heated by the laser, but at wavelengths corresponding to 915, 1210 and 1720 nm, subsurface lipids were differentially heated more strongly than water. The possible applications of this selective photothermolysis (heating tissues using light) include the selective destruction of sebum lipids to treat acne, as well as targeting other lipids associated with cellulite and body fat as well as fatty plaques that form in arteries which can help treat atherosclerosis and heart disease.^[25]

Biology[ed

Exceptionally bright and fast X-rays can image proteins using a sheet just one molecule thick. This technique allows first-time imaging of proteins that do not stack in a way that allows imaging by conventional techniques, 25% of the total number of proteins. Resolutions of 0.8 nm have been achieved with pulse durations of 30 femtoseconds. To get a clear view resolution of 0.1–0.3 nm is required. The short pulse durations prevented the lasers from destroying the molecules. The bright, fast X-rays were produced at the Linac Coherent Light Source at SLAC. As of 2014 LCLS was the world's most powerful X-ray FEL.^[26]

Military[edit

FEL technology is being evaluated by the US Navy as a candidate for an antiaircraft and missile directed-energy weapon. The Thomas Jefferson National Accelerator Facility's FEL has demonstrated over 14 kW power output.^[27] Compact multi-megawatt class FEL weapons are undergoing research.^[28] On June 9, 2009 the Office of Naval Research announced it had awarded Raytheon a contract to develop a 100 kW experimental FEL.^[29] On March 18, 2010 Boeing Directed Energy Systems announced the completion of an initial design for U.S. Naval use.^[30] A prototype FEL system was demonstrated, with a full-power prototype scheduled by 2018.^[31]

Optical technologies have greatly revolutionized modern warfare and battle plans. Sophisticated satellite surveillance systems,night vision imagers and missile guidance units have now given a new dimension to warfare.laser radiations propagating in free space are now used for targeting and range finding.

India is poised to have an exclusive pan-India Optical Fibre Cable (OFC) for its Defence Forces which will help them to vacate the radio waves they currently occupy. The proposal for the pan-India OFC is currently being processed and it will be to the tune of $ 1.3 billion.

The problem is that the copper wires are heavy and susceptible to the extreme environmental conditions of flight operations. Moreover, they do not carry electrical signals efficiently and cannot readily accommodate the introduction of new equipment because of bandwidth limitations. 

For those reasons, the Defense Department is slowly making the switch to fiber optics. In fiber, photons, or light energy, transmit the signals. A single fiber can transmit multiple signals via a process called wavelength division multiplexing. By using different wavelengths, or colors, of a laser, any number of signals can travel inside one fiber, said Raj Dutt, chairman and chief executive officer of Culver City, Calif.-based Apic Corp., which is executing the program. Shifting to optics-based networks and components would save the Defense Department a significant amount of energy, industry officials said. In coaxial cable systems, the electricity that propagates the radio frequency signals also heats up the copper wires. In photonics, there is no heat generation in the fiber because the information travels by light energy.

Have a look at the following link to know the history of optical fibers

http://www.timbercon.com/history-of-fiber-optics/

For collecting the data relevant to me I took the help of internet and browsed through many websites, journals and magazines in order to find the best article on my topic. Then I went on to get elaborate explanations and more informations on the various applications of photonics. Various youtube links helped me to know my topic better.

1. www.esjournals.org

2. I explored various videos on Youtube, and found some of them to be quite relevant to my topic.

3. Numerous articles available online on Phonic and quantum computing aided me in understanding the concept.

photonics is a very interesting topic and in order to understand the topic deepely internet indeed proved to be beneficial .I browsed through many websites ,read various journals ,took help from certain books .Various yuotube videos also helped me to understand the topic better

Article and other relevent information

http://www.timbercon.com/history-of-fiber-optics/

http://pyramid.spd.louisville.edu/~eri/papers_pres/harnesslight.pdf 

www.wsi.tum.de/Portals/0/Media/.../optical_lithography_nagel.pdf

http://www.nature.com/nphoton/index.html

http://www.ece.umd.edu/~davis/optfib.html

Videos

https://www.youtube.com/watch?v=zFnJQjcnhGQ

www.nature.com/n photon

www.photonics-marketing.com

https://www.rp-photonics.com/free_electron_lasers.html

www.nature.com/nphoton/journal/v4/n12/full/nphoton.2010.239.html 

https://books.google.co.in/books?isbn=1118225546

www.hw.ac.uk/schools/engineering-physical.../https://www.google.co.in/?gws_rd=ssl#

1. www.esjournals.org

2. www.youtube.com/watch?v=PQXl-atcBsg

3. news.mit.edu/topic/optical-computing

4. www.gizmag.com/photonic-quantum-computer-chip/38928/

5. http://arxiv.org/pdf/1107.4171.pdf

6. www.extremetech.com/extreme/187746-by-2020-you-could-have-an-exascale-speed-of-light-optical-computer-on-your-desk

7. www.sciencealert.com/new-tiny-silicon-chip-paves-the-way-for-light-speed-computers

8. www.cqc2t.org/research/photonic_quantum_computation

Check this link for the article on the use of optics in information technology

http://www.ece.umd.edu/~davis/optfib.html

Optical communications systems are very important for all types of telecommunications and networks. They consists of a transmitter that encodes a message into an optical signal, a channel that carries the signal to its destination, and a receiver that reproduces the message from the received optical signal

Mostly due to their very high data transmission capacity, fiber-optic transmission systems can achieve a much lower cost than systems based on coaxial copper cables, if high data rates are needed.

• The capacity of fibers for data transmission is huge: a single silica fiber can carry hundreds of thousands of telephone channels, utilizing only a small part of the theoretical capacity. In the last 30 years, the progress concerning transmission capacities of fiber links has been significantly faster than e.g. the progress in the speed or storage capacity of computers.
• The losses for light propagating in fibers are amazingly small: ≈ 0.2 dB/km for modern single-mode silica fibers, so that many tens of kilometers can be bridged without amplifying the signals.
• A large number of channels can be reamplified in a single fiber amplifier, if required for very large transmission distances.
• Due to the huge transmission rate achievable, the cost per transported bit can be extremely low.
• Compared with electrical cables, fiber optic cables are very lightweight.
• Fiber-optic cables are immune to problems that arise with electrical cables, such as ground loops or electromagnetic interference (EMI). Such issues are important, for example, for data links in industrial environment.

Target Audience- Researchers and IT professionals.

Questions for IT professionals.

1. Is there a need for increased processing power in present generation computers?

a. Yes, Its a necessity in the present times.

b. No, I think it would be overkill.

c. I am uncertain as of now.

2. Do you think increased horse power of computers will increase efficiency and productivity?

a. yes, definitely

b. no

Questions for researchers (people conducting research on optical computing)

1. How close are we to achieving this highly anticipated piece of technology?

a. Perhaps 2-3 years away

b. About a decade

Inferences I aim to draw.

1. List of all possible items that can be used for making optical microprocessors other than drawing glass (Silica).

2. The needs and requirements of humanity in terms of computing power.

3. Possible ways of increasing transfer channels while utilising minimalistic optical material.

All communications will employ fiber optics

a. In the near future

b. There will still be cables(they cannot be done away with)

c. No idea

It’s now time to say goodbye to the gigabyte and hello to the terabyte. What do you think about it ?

a. This is perfectly right

b. No, not yet

c. It still has a long way to go

What other materials do you think can be used for making optical fibers ? (for researchers)

Inferences I intend to draw

I would like to know about the opinion of general public about optical fiber communication

I would like to know about their awareness on this topic.

I would also like to know about the status of the research work being done in this topic

photodynamic therapy- It is a treatment that uses a drug, called a photosensitizer or photosensitizing agent, and a particular type of light. When photosensitizers are exposed to a specific wavelength of light, they produce a form of oxygen that kills nearby cells (1–3).

heliograph -- a device to reflect the sun's rays from a transmitting to receiving station using a code.

Attenuation- It is a general term that refers to any reduction in the strength of a signal.

EDFA- fiber amplifiers based on erbium-doped optical fibers

single-mode fibers--optical fibers supporting only a single guided mode per polarization direction

Multi-mode fibers--fibers supporting more than one guided mode per polarization direction

1. Optical Transport Network

It is a set of optical transport elements connected by optical fibre links, that is capable of providing functionality of transport, switching and management of optical channels carrying client signals.

2. Discrete Fourier transform

Discrete Fourier Transform converts of a finite list of equally spaced samples of functions into the list of coefficients of a finite combination of complex sinusoids ordered by their frequencies that has those sample values.

1. Optical computing in astronomy and astrophysics.

Optical microprocessors based computers can be used for faster and even more accurate analysis of astronomical objects. Researches for e.g. based on surface analysis of the planet Mars can be carried out at enormous pace using optical computing. The parallel processing powers of optical microprocessors are unmatched. They are capable of carrying out numerous analysis, varied in their approach on a subject. For e.g. optical computers can be used to process carbon dating data, water analysis, mineral analysis of martian soil together, which is not possible today until and unless you dedicate a mainframe computer for each process.

2. Optical computing in mobile devices.

Optical microprocessors or SoCs may be scaled down to sizes as small as a 14nm process, thus bringing immense processing capabilities to devices in your palm. If optical processing capabilities can be brought to smartphones and tablets it will aid the professional users who like to work on the go, for e.g. an increment in the number of channels of microprocessors for processing data will permit processing videos of extremely high resolutions ranging from 4K-8K simultaneously. This will specifically be of great use for a professional photographer.

1.  Real-feel Prosthetics

Researchers have made huge gains in the field of prosthetics, but with one major drawback: the user can’t feel what the arm is touching. That may change with the help of fiber-optic wiring—researchers are working on developing prosthetic limbs that the user can actually feel. By using fiber wiring to send pulses of light to the user’s neurons, the prosthetic limb will work similarly to a real one:sending information through the nervous system into the brain. While it’s still in the early stages, this could be a huge leap forward for prosthetics.

2.  Safer Lighting

We know that using electrical equipment, such as lighting, underwater is a big no-no. What you might not know is that fiber can be used to light areas that are normally hard to reach or dangerous to light, like pools. The fiber acts like a pipe for the light, allowing you to set up the light source away from the water so no one gets electrocuted! Because nothing ruins a pool party like an electrocution.So fiber-optics are helping to stop intruders, giving amputees their hands back, and saving people from being electrocuted? It sounds more like a superhero than a way to bring Detroit 100 times faster Internet!

2) commensurate-corresponding in size

3) emittance- ratio of radiant heat to that of standard black body

4)mitigate-less severe

5) epitaxy-artificial growth of crystals

6) speckle-dots

Optical fibres can be used in computer displays

Yes!

The entire computer display can be made out of optical fibers.

Optical fibers can be lit not only at its ends but also at selected regions.For this property, it can prove as a wonderful material for displays. Specific RGB colour contrasts are possible using optical fibres. This process turns out to be a one time investment, since the current displays tend to lose their brightness after certain years, while a completely enclosed optical fibre can sustain on a single streak of light for years all together. To be precise the current LED displays have an average life of 4 years, while an optical fibre based display can in turn last for at least 10 years due to design efficiency.

Optical fibre display technologies require a strong source of light.Traditionally, these sources have been bulky,heavy and electrically inefficient. The miniaturisation of LED type sources solves this problem,in part as LED's consume less energy and their electrical efficiency is higher,thus keeping the costs low. This solution of ours brings together the concepts of optical computing with optical fibre lighting.

1. What are the major challenges in building the optical computers?

a. Unavailability of raw materials

b. Technological barriers

c. Both

d. None

2. Are you willing to pay extra for the improvement in performance using this technology?

a. Yes

b. No

c. Depends on the final product

Inferences I aim to draw.

1. Awareness of the general public on the topic.

2. To give a rough idea, to the developers, at what price should the product be made available so that it should be consumer friendly

http://chemwiki.ucdavis.edu/u_Materials/Optics/Optical_Computing

www.ias.ac.in/resonance/Volumes/08/06/0056-0071.pdf

https://www.youtube.com/watch?v=bm6ScvNygUU

https://www.youtube.com/watch?v=1qQE5Xwe7fs

https://en.wikipedia.org/wiki/Optical_computing

2. SRAM-Static random-access memory is a type of semiconductor memory that uses bistable latching circuitry to store each bit

3. Computer paradigm-A programming paradigm is a fundamental style of computer programming, serving as a way of building the structure and elements of computer programs.

No, optical computer and conventional computers both have their advantages and disadvantages. For detailed idea read this articlehttp://130.75.63.115/upload/lv/wisem0708/SeminarIT-Trends/html/tr/right/5.%20Advantages%20and%20Disadvantages%20of%20Optical%20Computers.htm

2. Greater speed and accuracy of this technology can be very helpful in study of medical sciences.