all things NANO

Phone news: Serious competition for the iPhone

Adi Narayan — Thu, 14 Jun 2007 17:04:04 +0000

This is the rPhone. Given the inordinately high costs of steve’s baby, you may want to consider this one ..

Lasers from Quantum dots – Los Alamos team just solved the big problem

Adi Narayan — Thu, 14 Jun 2007 16:49:58 +0000

This is really a important feat. For making a laser,you need to go through two steps – population inversion and stimulated emission. The inversion stage comes when the majority of the electrons in the material are in the excited state (conduction band). When this is the case, any incoming photon of the right energy “stimulates” the electron-hole pairs to recombine and emit two more photons.. This is stimulated emission, and leads to the photons getting amplified.

With Q-dots, the problem was that the pop inversion state lasts for a very very short time – less than 100 picoseconds. If you have to get emission within this time, you need some really fast lasers – which are really quite expensive.

These guys achived a breakthrough in this regard. I interviewed them and wrote an article for Optics magazine. You can find it here.

Quantum dots are really quite amazing substances. In a simple sense, they are like a container which holds electrons and holes in an incredibly small space. However, the confinement is not because they are like physical “containers”, but more because the bandgap values are specially tailored in a way that the charged particles cannot get out.

Father of the laser passes away

Adi Narayan — Wed, 13 Jun 2007 05:26:33 +0000

(pretty late) Nature has published an Obituary for Theodore Maiman – the man behind the laser. He was the guy who made the first Ruby laser. At the time noone could visualise any use for this device, and so they called it “A solution without a problem”. He passed away on 5 May 2007. Twice nominated for the Nobel, and recipient of many other national and International prizes

Here is a NYTimes article on the same .

Detecting skin cancers with lasers

Adi Narayan — Mon, 11 Jun 2007 16:54:29 +0000

Folks at Duke Uni have made a system that fires low power lasers on the surface of the skin and checks for telltale signs of Skin cancer. It fires out a series of beams and finds the concentration of haemoglobin and melanin – two chemicals inherently present in the skin. The relative concentrations can give an idea if cancerouns growth is happening or if its just some simple wart or something.
- It works with femtosecond lasers and employs pulse shaping >> thats going to be pretty expensive.
- The setup is really BIG (look at the article below), and they got some really shrinking to do..

http://optics.org/cws/article/research/30237

And a link to an article I wrote about a Purdue Uni team that used holograms to find how anti-cancer drugs are faring..

http://optics.org/cws/article/research/27475

Setting off..

Adi Narayan — Mon, 11 Jun 2007 16:30:50 +0000

This is a blog to track the new developments in nanotechnology, photonics, optics, LED’s, Lasers and all.. Feel free to add your comments and suggestions any time !

Here’s to an exciting time ahead

Hello world!

Adi Narayan — Sun, 10 Jun 2007 14:50:18 +0000

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!