Grant me a break!

This week is madness: the submission deadline of all the grants in Photonics seem to be falling in it. Which means that if one intends to apply for even a few of these grants, it is working till you reach ‘zombie’ level!

So I am applying for 2 Royal Society grants, one UKIERI grant. The deadlines are 28 and 31 May. Giving me no time to breathe.

The RS equipment grant (28th may deadline) was easiest to apply since there was little dependence on other people and no coordination required. The other two however are a different story: one is a grant to organise a 3 day workshop and the other is a research project between Indian and UK partners. Which means working with international partners, getting letters of support from various Heads of Department, agreement to participate from several people, working out budgets with many partners etc. etc. 

While I hope the applications will be successful, right now I feel buried. I need a holiday!!


Au Revoir, Munich!

You may wonder why I didn’t write a post entitled, “Thursday at the Laser World of Photonics”. Well the reason is that I didn’t get much time at the conference at all!

The day began badly with the front desk staff at the hotel having bungled up my reservation, and after spending some time with them it was still not resolved. So I left for the conference, and took the U-Bahn only to reach Joesphsplatz on the network to find that there was some trouble and the trains were not going till the station that serves the venue. So it took me 2 hours and some back and forth on the train, a bus ride to get there. I then spent some time trying to find emails and documents that would resolve my hotel problem, had lunch and then hurried back to the hotel! As you can guess, I didn’t really attend many presentations.

So a bit of a bummer.

However, I enjoyed my stay in Munich overall. I have already spoken of the technical talks that I heard and particularly liked. I did do more than that though, as you would expect!
So I enjoyed the Weissbier which I sampled from no less than 3 different breweries over the weekend after the conference. While visiting the English Garden I also saw some intrepid young surfers in action in the small river/stream that runs through the garden. I visited some old churches, bought a pair of snazzy sunglasses, lots of chocolates and eventually a cuckoo clock (for my brother) from the Munich Airport. Walked around Marienplatz, took the tram and basically felt that Munich is a lovely, graceful city.

I hope I get to visit for another conference!

Wednesday at the Laser World of Photonics

The highlight of the day for me was the talk by Shanhui Fan of Stanford University on nanophotonics in light management for thermal and solar applications.

He discussed in brief three different concepts. He started with the role of nanophotonic structures on solar cell surfaces and within solar cell structures, to reduce reflection and increase both the short circuit current and open circuit voltage! He then went on to talk about how while our focus is on getting energy from the sun, for applications such as cooling buildings (power for air conditioners) another more feasible approach would be to exploit the properties of a sink! The vacuum that surrounds us has an average temperature of 3K,so we could sink our heat to it. This is such an innovative thought! But how do we do this? Again he showed some results. By making certain nanophotonic gratings of SiC etc. it is possible to give them strong thermal emissivity in 8-13micron range in which the atmosphere is transparent- allowing this radiation to go away into space. This could be an effective way to cool buildings, extract heat! He also presented an idea on how thermal extraction enhancement that without breaking the Stefan Bolztmann law, still manages to improves the performance than a conventional black body!

Some papers cited include:

Nature communications, vol. 4, pp. 1730, 2013

Nano letters,Vol. 13, pp. 1451, 2013

Optics express, Vol. 21, pp. 1209, 2013

Nano Letters, Vol. 13, pp. 1616, 2012.

Happy reading!

Tuesday at the Laser World of Photonics

Of dwarves, giants, weissbier and attosecond pulses!

That was my day in a nut shell.

Well I’ll begin by summarizing some of the technical stuff:

The talk on attosecond science was a tutorial type 1hour long talk by Paul Corkum. For me this field is completely new and I thoroughly enjoyed learning about pulses created from sub cycle phenomena! The idea is that when the E field of an em wave helps an electron tunnel away from the atom (in the process gaining some kinetic energy without dephasing) then on its return to the atom, the electron gives up this energy in the form of an attosecond pulse.  So there is plenty involved in creating and detecting these pulses. how can this be used? Well for me the use might be in exploring the response of materials at attosecond scale and see if we discover new physics. While in the talk Prof. Corkum discussed how these pulses are being used to image orbitals in atoms. Imagine that!

Now to dwarves and giants:

If you have been to a conference, you will know what I mean when I describe this: tall guys (giants) who gravitate towards the front end of the seats, right in the middle of the row so that shorter people (dwarves such as myself) can only see about 20% of any slide. We dwarves then have to constantly move left and right like crazed tennis watch matchers to find a chink in the wall of attendees ahead of us, to catch a glimpse of the slides. It is very annoying! Why cant the giants sit nearer the back? They will still be able to see the slides. Also, the dwarves will silently thank them for it!

The weissbier!

The conference dinner was another traditional Bavarian affair in a big restaurant/hall where we were served some delicious local cuisine. But the best was the excellent weissbeer. This beer contains a good proportion of wheat and hence tastes different from most beer. Now I am not a beer fan, so I tried this somewhat gingerly, but I found it most refreshing and tasty. So while I am in Munich I think I will be visiting some beer gardens and chugging down some more weissbier, though not quite as many 500ml tankards as the locals!

Monday at the Laser World of Photonics

So the Bavarian adventure continues! The evening had a Bavarian evening hosted by OSA, which was great German beer, traditional food and some song and dance.

Today was a fun and very tiring day again at the conference. 

So what did I attend:

  1. Optofluidics in Energy Applications by Demetri Psaltsis, EPFL Lausanne.

This was a brilliant talk giving an overview and idea of the research topics in this fascinating area. The focus was on applications for energy and that was my interest. He explained different how solar energy is used in solar fuel (convert one fuel/chemicals to another); solar thermal (use solar light to heat up liquids)… The thing I found fascinating was his explanation of why photosynthesis in plants/leaves is very inefficient! Apparently the efficiency is as low as 1-2%. The key thing is that water contents in leaves etc is heated and escapes as vapour, creating a negative pressure, because of which water moves up to the leaves from the roots, trunk etc. All this because plants too have an optimal temperature (about 20degrees Centigrade) and need to cool down. So essentially photosynthesis as a process only providing part of the energy needs of the plants, while the heating of the fluids is moving huge amounts of water and expending lots of energy! This is also a reason that bio-mimetic PV should not look at photosynthetic processed as an inspiration. Some papers from this group mentioned in the talk include: Optics Express, Vol. 21, no S3, pp A460, 2013; Nature Photonics Vol. 4, pp. 583, 2011.

2. Mode instabilities in LMA fibers: the speaker gave a great over view of this barrier to power scaling of high power fiber lasers. The basic idea is that apart from effects like SBS, SRS, damage threshold of materials, and heating of fibers, there exists another issue. This issue is that for most fibers after power increases above a threshold, the mode changes and seems to oscillate between higher order and fundamental modes.  This generates an interference pattern which affects the mode inversion of the fiber laser, leading in turn to an inhomogeneous temperature profile and due to the thermal properties of the material this creates a refractive index grating. As the pump power is not absorbed homogenously the power scaling gets limited. Some papers from this group mentioned in the talk include: Optics Express, Vol. 19, pp 13218, 2011; Optics Letters, Vol. 35, pp. 94, 2010; Optics Express Vol. 20, pp 11407, 2012.

3. Quantum Coherence at the level of a individual light harvesting complexes.   In this fantastic talk from the group of Nick van Hulst, were presented results for light harvesting by a bacterial complex. So essentially bacterial photosynthesis. The transport of the excitation energy was found to be almost 95%! The possibility of quantum coherence leading to such high efficiency was discussed. They cited Brinks, Hildner et al. Optics Express, 2011. This talk has given me a reason to go back to the Quantum Mechanics textbooks and undertand quantum coherence.

I also saw part of the exhibition and got lost! It was HUGE! There are about 1000 exhibitors so you can imagine. In trying to see the entire exhibition in 1 day (mistake and could not manage it anyway) I ended up missing the poster session. Bummer!

I hope to make it to the posters tomorrow. Till then!

Sunday at Laser World of Photonics

A wet and somewhat chilly start to the conference took place in a simply massive facility… I think it can hold a huge number of people. The tube station is 2minutes walk to the centre and very conveniently located for visitors.

So what did I start with:

Well as my blessed hotel doesn’t have wi-fi (for over 100€ a night I think that is a crime!) I started by checking my emails since something urgent needed to be dealt with.

Having done that I could now concentrate on the talks!

The talk I found most interesting was by Prof. Lihong Wang of Washington University in session CL-1, a tutorial on Photoacoustic Tomography and part of the ECBO meeting.  He made the points that both the optical diffraction limit (which limits the resolution we can get in image to 2x wavelength being used) and the diffusion limits have been overcome to some extent by Photoacoustic Tomography and Microscopy. The principle behind photoacoustic effects is that light when shone on tissue heats it up and due to the thermoelastic effect there is emission of phonons or acoustic waves. These can then be detected. When the non-linear response in emission of the acoustic waves is exploited the diffraction limit can be overcome. He went on to briefly differentiate between tomography (in which mathematical triangulation is used to resolve/focus the signal) and microscopy (where the detection process focuses the beam). He showed several fascinating images of imaged tissue/organisms from these techniques. I wish though that he had spent a little more time on the physics of the technique.

Then I enjoyed a contributed paper on optical activity in twisted PCF (session CK4, 1st talk). The authors have used a quantum formulation to understand the modes and birefringence in twisted PCF. Those of you who know my interest in spiral PCF would immediately see why this talk appealed to me! I sat through this entire session.

But was gutted to have missed the sessions on Theory, Algorithms and Modeling which are part of the ECBO. These sessions included talks on modeling methods and their role/latest in biophotonics…Blah! But then its impossible to be everywhere at the same time.

Two posters that gave me something to look up on:

  1. Poster CC-P7, the idea that coupling to metal wires form propagating modes for THz improves significantly if they are radially polarized. In fact attenuation and dispersion properties are supposed to improve markedly… (they cited Optics Express, Vol. 20, pp. 21896, 2012).
  2. Poster CA-P.19 which discussed merits of end and side pumping of Nd: YAG lasers by solar light!! I didn’t know that solar light could be redirected, collected and concentrated and then used to pump solid state lasers. So this is a fantastic thing I am going to explore. A reference they cited: Laser Physics, Vol. 23, pp. 065801, 2013.

But before I end, I must moan about two things:

I managed to crash Thomas Krauss’s short course on Photonic Crystals, and he had to ask if I was registered for it and I had to leave (as I wasn’t!). Embarrassing! How could I mix up the sessions so badly?!

Second is a genuine gripe: there long queues for food in the cafes in the centre, so many people ventured to the McDonald’s and the few open eateries to get food (braving the rain!). There were several other places to eat there but all closed on account of it being Sunday. Now, why start the conference on Sunday when the infrastructure is not wholly functional? Also, it means a weekend gone for most folks attending. Just start on Monday!

Well more soon tomorrow!

Hello from Munich!

I am here in Munich to attend the Laser World of Photonics conference which combines several meetings: CLEO Europe, European Conference on Biomedical Optics, Optical Metrology, Lasers inManufacturing…

As you can imagine, its a huge affair! There are many many attendees and the programme has so many sessions and talks that its mind boggling.

Well, what I intend to do in the next 4 days is to write short blogposts on the talks I hear/posters i see in the conference. I hope that you will enjoy that.

Meanwhile first impressions of Munich:

Pretty city but expensive… my hotel costs a bomb (or so it seems for more than a 100euro a night and doesnt even have wi-fi!) . the metro/underground is great. very easy to use. Since i arrived some what late last night on a Saturday evening, wasnt sure about finding food at 10pm. But had a very very lovely Vietnamese dinner at a place called Koriander in the Scwhabing area. Guess you will be hearing from me about food and sites and shopping as much as the talks!


Spacewalks, Mars, and more… humans in space!

Space exploration has been part of ambitious  programmes run by United States,  Europe, Russia and others. Most of these

Cartoon of Yuri Gagarin opening a door looking into space

programmes are funded and run by governments who may use private firms as contractors to source space craft parts.The farthest a human being has gone into space is perhaps the moon landing of the 1960s. Since then space walks by different astronauts have taken place and we have astronauts in the International Space Station, though the overall emphasis was on unmanned exploration.

In space exploration, apart from the question of manned versus unmanned, there has also been the rise of the question of government versus private. The complex technological and investment heavy field has led to many companies supplying parts to agencies such as NASA for their missions, and conducting research for them. More recently the International Space Station has been serviced by rockets launched by the company SpaceX.

We are now on the threshold of an entirely new space scape: The private individual having access to space!

Private companies such as the Virgin Galactic and Golden Spike (and others, see link) have been set up with the express purpose of launching missions to take (suitably cash rich) people into space/moon, exploring space and mining on asteroids/moons. While Inspiration Mars want to take human being near/on Mars and Mars One wants to create a human settlement on Mars, see this article

Is this the entrance to the rich world that sci-fi writers such as Robert Heinlein, Arthur C. Clarke, C.J. Cherryh  and others have so wonderfully created?

Going into space: the idea thrills me to my very core (see also my blogpost “…A Homage to Voyager I”. Yet the idea of unfettered (the only constraints being money) space exploration and exploitation make me deeply nervous. Our history of finding new lands and then colonizing them and their indigenous peoples is not particularly complimentary to us. The idea of colonizing in and of itself is something I find distressing. But besides that, there are other concerns

Will we be welcomed by other species (if advanced enough)? Will we be writing our own version of the Martian Chronicles as opposed to Bradbury’s fantastic fiction? Can we co-exist harmoniously with those who are different from us? John Wyndham and China Mieville have posed this question in their novels in a most entertaining read.

We will find our own answers to these questions in time. And to those questions that we have not yet thought of. I hope the journey is one of discovery and not one of carnage.