Monday, March 14, 2011

Infinite opportunity for research in photonics

Biophotonics provides immense scope for research. Biophotonics is a fusion of photonics, nanotechnology, biotechnology and lasers. A basic idea about activation of biomolecules by light, and the resulting photoinduced processes, is the elementary need in making new probes and drug delivery systems. Moreover, a knowledge of multiphoton processes making use of laser pulses which are ultra short is needed to develop new probes and create new modalities for therapy activated by light.

Some areas of opportunities:

Physical principles of biosensing and imaging
Research in Photoprocesses in bioassemblies and biomolecules.
The study of single-molecule biophysics.
The use of nonlinear optical processes in therapy.

Biomedical Researchers
The study of cellular mechanisms of the action of drug.
Research in toxicity of photo activated materials.
Bio-imaging to find out cellular, and tissue functions.
Optical technique for early detection of cancers.
The study of bio-compatibility of implants.
Dynamic imaging for physiological response drug delivery.

 Clinical studies of side effects.

 Development of optical in vivo probes for infections and cancers.
 The various techniques for tissue welding.
 In vivo optical biopsy.
 In vivo optical mammography.

 Targeted therapy using nanoclinics.
 The use of nanochemistry for probes and nanodevices.
 The study of newer structures for optical activation
 The creation of new fluorescent tags.

Nanotechnologies for targeted detection and activation.
Development of new noninvasive light activation.
Development of optical bio MEMS (micro-electro-mechanical systems).
The integration of new generation lasers, delivery systems, and detectors.
Automation and miniaturization.

Wednesday, March 9, 2011

Terabyte Data Storage In Sugar Sized Crystal

Yes it is possible to store one Terabyte data in a sugar cube sized crystal. It is a 3D memory storage device. In most memory storage devices like magnetic and optical storage devices, the bits of information are stored along the surface. However, in holographic memory storage device, the information is stored making use of the entire volume of the medium and is able to record images in the same area making use of light at different angles. Thus using holographic technique it is possible to read and write millions of bits in parallel. 

Recording Data
As shown in figure, the laser is split into two beams by the beam splitter. One portion of the beam travels through the spatial light modulator. A Spatial light modulator (SLM) can be a liquid crystal display with the data pattern to be written appearing on it as dark and bright spots. The beam after passing through the SLM, is made to combine with the reference beam and produces an interference pattern which is stored onto a particular region on the crystal. This region can be varied by adjusting the writing beam angle. this enables data to be stored on same area but at different region within the volume.

Reading Data 

In order to get the stored data, the reference beam is made incident onto the crystal at the same angle at which the data was written.

Saturday, March 5, 2011

Optical Dynamic RAM

The current internet speed is limited by the node switching speed. This is because a conversion from optical to electronic and then back to optical is required at a node. This is obvious because the current packet switching is being done at the electronic level. A packet is used to carry information over the internet. this packet need to be switched at each node to reach the destination. Packet has header to identify the destination. Depending on the header, a packet is rightly directed to the destination. However, this is being carried out in the electronic domain.

Optical packet switching is technique which will enable this to be done in the optical domain and at a much higher speed. To enable optical packet switching, there is a requirement of optical random access memory (RAM). Optical RAM can be used for queuing packets at a node which are to be switched. The possible solution to an optical RAM is to use an erbium doped fiber. Erbium doped fiber acts as an amplifier. The amplification provided by erbium doped fiber is not what Optical RAM is concerned with.But, the fiber doped with erbium can be made to show two states namely- absorption state and transparent state, which are analogous to 0 and 1.

Deoxy ribonucleic acid - DNA

You might be wondering what does DNA have to do in Optoelectronics. I recently read that DNA based materials  had optical properties and could be used in photonics in various applications. The double helix structure of DNA is awesome. Apart from being used in cloning, genetic mapping, and crime investigation, DNA is now appearing in clean rooms of semiconductor and thin-film coating facilities. It turns out that DNA, when concentrated into a thin-film bio-polymer through reactions with surfactants, can be used to create improved optoelectronic devices.

  Fig DNA as material for synthesis into bio-polymer thin film that can be used in many optoelectronic devices

Making DNA biopolymer into a commercial material is the aim of researchers like Steckl, who are attracted by optical and electrical properties of thin films of DNA biopolymer.
“These DNA-based materials possess unique electromagnetic and optical properties that no other known polymers have: low optical loss over a broad wavelength (350 to 2000 nm) and five orders of magnitude more conductivity,” says James G. Grote, principal electronics research engineer at the Air Force Research Laboratory Materials and Manufacturing. I am Looking forward to hear from you all about your findings and opinion about the topic.

Wednesday, March 2, 2011

Optoelectronics will take over the future

Now that you are reading this right now reflects that you are interested in knowing about what the future technology revolution would be like, and what all are the suitable career options. Electronics dominated the last few decades and VLSI made it possible to built the computers as that are now available. But, however the requirements of speed and performance of computers is ever increasing. This is where a new technology will be essential. This is because there is a limit in the speed possible using electronics. This is because electrons are used in an electronic system to operate. Light has got the maximum velocity and hence it is obvious that it is fastest in processing. However, using light to process data and perform optical computing is an idea that has come up long before the time of computers. The reason why the task of computing was done using electrons was that no technique was known to make light to compute. With the invention of LASER and realization of simple logic gates, optical computing has become an area of research. The spark has already begun. A cost effective fully functional optical transistor is a challenge. A lot of realization of optical transistors have already been made. But, the cost needs to be reduced and performance to be optimized. All of you who are interested in taking up new interesting fields of study should definitely choose this stream of study. I have taken Optoelectronics and Communication as a part of my M. Tech course. The scope of Optics is not only limited to computing, but sensing, bio-cal applications using Bio-photonics, high speed communication and so on. The reason for me to start this blog is to guide aspiring students who are taking up this filed of study to get basic awareness of the possibilities in the field. I would also be posting interesting projects and seminars in optoelectronics. I will include seminars, ebooks, pdf and interesting readings on biomedical diagnostic application of photonics, optic fiber sensing, industrial photonics, bio photonics and integrated optics. Digital Optical Signal Processing is an intresting area where a lot of research is being done.