Showing posts with label Optics. Show all posts
Showing posts with label Optics. Show all posts

Friday, 27 October 2017

Material Could Bring Optical Communication Onto Silicon Chips

Soon silicon chips will feature optical communication with the discovery of a new material

With each passing year computing performance has advanced significantly and if we take decades into the equation then you will be astonished at the rate of advancement. Computing performance boost has been achieved through squeezing more number of transistors within a relatively tighter space on the microchips. Now scientists have been able to develop such ultrathin films placed on the semiconductor making optical communication possible on the microchips.

The ‘interconnect bottleneck’ in optical communication

The downsizing of the microchips over the years had led to signal leakage between the different components which eventually results in slower communication between them. This delay in communication has been termed as ‘interconnect bottleneck’ which has emerged as a major issue in the high-speed computing systems.

One of the best ways to eliminate the interconnect bottleneck in microchip is to make use of light to allow communication between different parts. Using wires for communication is simply out of the question but even using light isn’t a simple or easy way as silicon used to make chip doesn’t’ happen to emit light easily.

Finding a new material to emit light

Researchers have found a light emitter as well as detector which can help in bringing optical communication by integrating it in the silicon CMOS chips. A new device has been built from a common semiconductor material, molybdenum ditelluride, which belongs to a new revolution group of materials called two-dimensional transition-metal dichalcogenides.

The best thing about this material is that it can be stacked right top of the silicon wafers which wasn’t the case earlier. This 2D molybdenum ditelluride is such a remarkable ultra-thin material that it can be easily attached with any material without much hassle. A major difficulty faced by the scientists while looking for materials to integrate with the silicon semiconductors is that most of materials happen to emit light in the visible range. And silicon is notorious for absorbing the light emitted at such wavelengths. While molybdenum ditelluride happens to emit light in the infrared range which can’t be absorbed by the silicon and thereby it helps in enabling the optical communication on the microchip.


Future prospects of this new discovery in optical communication

Researchers have stepped their efforts towards finding other materials which can also be used for the chip based optical communication in future. Currently most of the telecommunication system operates mainly using the light having the wavelength of 1.3 or 1.5 micrometers. The good thing here is that molybdenum ditelluride happens to emit light at 1.1 micrometer which is suitable for usage in the silicon chips found specifically in the computers but unsuitable when it comes to usage in the telecommunications systems.

Therefore researchers are again looking for a new material which can help initiating the optical communication the telecommunication systems. Currently they are exploring another ultra-thin material known as black phosphorus which has the potential to emit light through altering the different layers used in the process. This research has been published in the science journal called Nature Nanotechnology.

Tuesday, 14 October 2014

The Rochester Cloak

Rochester Cloak
Great headway has been done at the University of Rochester in New York by scientist who have created a cheap` invisibility cloak’, in an attempt to hide objects from view. Researchers at the University of Rochester probably were inspired by the invisibility cloak making several attempts with some simple as well as some involving new technologies and with the combination of optical lenses, any object which passes behind a particular line of sight would seem to disappear from view.

This latest creation which has been developed at the University of Rochester has not only overcome the limitations of earlier devices but has also used inexpensive and readily available products in a novel configuration.

This creation which has been dubbed `The Rochester Cloak’, has utilized simplified four lens system which bends light around an object that may be placed in the centre of the chain and one is able to view the normal area in the background, though not the item in the foreground. It can be scaled up with the use of any size lens according to its inventors and the team who have been responsible for the setup have utilised standard off the shelf hardware.

First Device – 3 Dimensional 

According to John Howell, professor of physics at the University of Rochester, several approaches to clocking have been made while the basic idea behind it all was to take light and pass it around something with the idea of it not being there, which is often done with the use of high tech or exotic material.

Howell together with Joseph Choi, a graduate student,by forgoing specialized components, created a combination of four standard lenses which tends to keep the object hidden while the viewer moves up to some degrees away from optimal position of the view.

Choi states that this has been the first device with a three dimensional continuously multi directional cloaking that works in transmitting rays in visible spectrum.Howell states that several designs on cloaking tend to work well when viewed straight on though, if the viewpoint is moved a little, it tends to become visible.

Choi adds further that the previous cloaking devices could also cause the background to shift greatly making the presence of the cloaking device obvious.

Mathematical Formalism for Cloaking

Rochester Cloak 1
The researches in order to cloak the object as well as leave the background undisturbed tend to determine the type of lens together with the essential power and the precise distance to separate the four lenses.

In order to test their devices, the cloaked object is placed in front of a grid background and as they look through the lenses changing their viewing angle, done by moving from side to side, the grid shifts accordingly as though the cloaking device is not present.

There is no discontinuity in the grid lines behind the cloaked object when compared to the background and the matched grid sizes. Howell and Choi have provided a mathematical formalism for cloaking in a newspaper which was submitted to the journal Optics Express as well as available on, which can work for angles to 15 degrees and above.

A technique known as ABCD matrices is used to explain how light bends when passed through lenses, mirror or any other optical element. For More technology news visit Mono-live often.