Radio is the new star along with the photonic radar

I dont think video ever really killed the radio star, perhaps outshone it to an extent?

Never the less, the new inventions in radio are certain to shine bright: software radio!

As most of you would already know, to send and recieve information on radio waves, the modulation and demodulation required is done by dedicated electronic cicruits that work for particular frequency bands and setups. So its not possible to switch bands and a radio/system set up to work in a particular country/band/ etc. cant be used to transmit/receive other signals (say FM instead of AM or wifi or tv) or in different countries.

With software radio, a piece of software performs the modulation/demodulation on the software that represents the signal. So literally any signal can be used in this setup. The Universal Software Radio Peripheral (USRP) works as the hardware which converts the actual radio waves/signal into software that can be used with the radio software program.

The potential benefits of software radio can be huge: the same system could be a radio or a TV, wifi transciever even! One place where it may well prove to be a big hit is the photonic radar.Using software radio it would be possible to replace several components (each of which performs a dedicated task such as sending out signals or detecting them etc.) with one lighter, energy efficient and more versatile equipment for the photonic radar.

The photonic radar has recently made big news due to its connection with the missing Malaysian Airlines flight. However, the invention itself is ingenious: by heterodyning (or producing beats) between two modes of a mode locked laser so the phase of the resulting signal is very stable, it is possible to use the signal for radar. One can go to higher frequency ranges and broader bandwidth compared to traditional electronic circuits that produce signals that are noisy at hgih frequencies and have limited bandwidth.

This combination of photonics with digital radio offers a great new solution that overcomes several problems simultaneously. I found this really exciting and am looking forward to learning more about it in the future.

A non-linear response

For most practical things we expect that the effort we put in to achieve a goal is proportional to the expected reward. A sort of linear response curve.

So I am endlessly fascinated by the non-linear response on display when it comes to competitions. In many fields such as robotics, rocketery and others, competitions (and historically there have been several) are held with maybe a small prize on offer.

The desire to compete, to pit their wits (and designs) against others’ seems to drive people to such an extent that they invest far more than the prize money may warrant. The resluting entries in competitions vary from ingenious to the ridiculous. Yet the special spark that competing lights, gets the creativity of people blazing. What this also does is generate a huge amount of brilliant new ideas that can be used by all of mankind.

This is recongnised by for example, the XPrize foundation which holds a number of competitions in various fields.

To me the investment (from the point of view of the organisers) is miniscule compared to the outcomes and generated wealth (of intellectual capital). It sure seems to beat paying a steady salary to bright epeople, when a small fraction can get you something that would take years to achieve!

Technical education

I recently enrolled in the University’s MA in Academic Practice programme to learn about well, learning and teaching. I am keen to enhance and improve my teaching using the latest technology available as well insights that learning theory can give.

So I entered the world where humanism and meta cognitive theory[1] (and many others) are approaches within the context of which learning is looked at. How do these frameworks impact teaching design, curriculum, learning, assessment and so much more.

The impact of technology in terms of the “blended learning” environment, “chunking” and how our information processing capability is limited [2], reflection, wikis… all this has now entered my life.

Perhaps it is this interest that has led me to noticing more articles about teaching or maybe more people are writing about it in STEM, I do not know.

In a recent issue of Physics World devoted to eduation, many articles addressed making Physics more interesting to young students (ages 5-16), designing curriculum with this in mind; about educating or informing general audiences about Physics using Youtube.

In other posts I have mentioned Just in Time teaching and topdown approaches to teaching that some people advocate: talk about a big problem (how does you recognise a picture?) that interest students and then breaks them down level by level to get them to the concepts they have to learn in the class/module. This keeps more students engaged than the regular approach of bottom up..

I am yet to find an article/theory/approach about effectively teaching mathematical content (within Physics for example) at university level. My class has a large distribution in terms of both interest and ability in Mathematics: some students enjoy it and are adept while others find math difficult and scary. The challenge is how to engage and develop the ability of the weaker students. In my view (everyone may not agree) it is difficult to go to a higher level in Physics without being able to do Mathematics.

If you have any ideas on how to solve this puzzle get in touch!

1. Anderson, T (ed), Elloumi, F (ed). (2004) Theory and Practice of Online Learning.
2. Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63, 81-97

International Womens day

International womens’ day comes about in March every year and much like many years there has been a bit of hype around it. The occasion is used by various womens’ organisations, policy makers, governments, to raise awareness of issues connected to women. The media is an important component in this ever growing do. And commerce is never far behind in exploiting every possible opportunity (behold the offers to women in shops: shop for more than x amount and get 10% discount. Never mind taht the amount you need to purchase is huge and the discount is measly)!cartoon on womens equality

For the scientific community does this day have relevance?
The answer is yes. The so called STEM (Science, Technology, Engineering and Mathematics) fields historically right up to this day have a massive under representation of women. Plenty has been written about this gap and for some years there have been attempts to address it. Groups like MWOSA are testament to this.

In this article I want to address what I see happening in the future that can make a positive change as well as what all of us can do.

Celebrating female successes and creating role models is becoming a big part of the prevalent thinking. We will see more and more that groups (MWOSA, IEEE Women in Photonics, Women in Physics) and many others bring to the fore the achievements of their female members (through award ceremonies, magazine articles) . This explicit recognition and celebration of successful women scientists will also go towards showcasing them as role models to younger women and girls. For example, check out the We the Geeks Google Hangout series at the White House which celebrate some very cool women role models.

Womens’ networks are getting a boost. The power of networks in helping members make connections (to get that job or promotion or new project) is widely recognised. Traditionally women tend to have narrow but deep networks (compared to male counterparts who on average have wide but shallow networks) and may often hesitate to ask for help unless they know a person very well. Increased training and awareness in all female networks are catering to some of the specific behavioural styles women have.

Is there something that we can do as individuals?

Research has shown that women are also prone to unconscious bias like men. Therefore when it comes to interviewing candidates, peer reviewing proposals and papers, women and men, both unconsciously (where direct prejudice is absent) tend to favour male candidates. Even when the gender is unknown, a name that seems “male” tends to get higher approval. Our understanding of unconscious bias is now better.

So one thing that each one of us can do is to introspect and perhaps take tests like (the Implicit Association Test) to check our own tendency towards unconscious bias and eliminate it.

Another perhaps an even more powerful strength we all have is our voices. As members of OSA and other technical bodies we can volunteer in outreach efforts to young girls, it is possible to act as mentors to younger members, and also to ask the society to prioritise equality in its policy.

Many large corporations and businesses now train their recruitment managers on unconscious bias and treat it as a serious issue. They do not want to lose good talent because of such bias. In addition there has been discussion on creating quotas for women in boards of businesses. Some countries like Norway have implemented it while in others targets have been set for businesses. The point is that the business world and policy makers are addressing the under representation of women at the top level. Talent and ability are just as important here as in STEM, so the solutions being looked at do not compromise on quality.

Scientific bodies, research institutions and higher education bodies have not yet set targets (for female representation) or openly discussed quotas. Perhaps these can be thought of in different forms: gender balanced editorial boards for journals, conference committees etc. As members we can contribute to this debate and bring it to centre stage.

OSA and IEEE Photonics are in many ways trend setters: with OSA CEO Elizabeth Rogan and the immediate past president of OSA, Donna Strickland, Dalma Novak the President of the IEEE Photonics Society all being female, this sends a powerful message to all the young women in Optics: you can get to the top.

It is too much to handle!

My best friend has been pestering me to download “Whats app” on my phone so that we can chat via text when ever we feel like. My neice wants me to download “Facetime” so we can talk for free when we like. The list of apps/software that I am being told to download, install and use for “all the time connectivity” seems to be endless! I just cant handle it!

I am not anti social and really enjoy talking to my friends and relatives. Some of these software and apps make it even easier to keep in touch with loved ones, especially when we live on different continents, so I value them.

But I have a horror of being always available.

Because it means I can never completely switch off or just relax. There is always someone who wants your attention and even if it is your bedtime you feel somehow pressured to respond. On holiday the temptation to check office emails is irresistible. The first thing many of us do when we get home is to switch on the laptop and look at the new mails in the inbox since 45 minutes ago!  There is always some one waiting to reach us from across a time zone and the technology now allows them to do it easily. Our minds are now always alert and it seems like we can never go into sleep mode like some of our electronic devices. I find this hugely tiring mentally.

Another impact this has the inability to concentrate on one thing. I feel so anxious that I am missing something that I must do two or even three things at the same time. More and more I notice that people are always fiddling with their phone/tablet/gadget when talking to someone/watching a film/relaxing. No more the time for focusing on one thing or person at a time. It is like being hyper children who cant sit down and eat a meal at the table! Our attention spans are shrinking rapidly.

It does not end at these sort of software and apps that human beings use and can thus regulate their behaviour and use of (do not text or whatsapp or facetime people when you expect them to be sleeping!). Many of our devices and software constantly beep at us, show pop-ups on our screen, send us messages etc.: in short these systems demand our attention agressively. The intention was probably to give us useful news/information about the system. But somewhere along the line the systems have taken on a life of their own. They are now in the foreground, while we keep placating them with completing updates, blocking pop-ups, setting cookies, downloading apps, doing virus scans and many more sophisticated things, just to keep the machines and our lives running!

This invasion of technology that is constantly demanding atttention is just crazy. Mark Weiser said in the Scientific American, “the most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it…. “

I wish we could find a good balance that lets us use technology without letting it ruin our mental and emotional health!


By artiagrawal Posted in General

Opening minds in Delhi

Hey! You may have wondered why I didn’t post anything new here for a few days..I was missing in action so to speak. I am in Delhi to attend a workshop on computational photonics co-sponsored by the Royal Society and the DST of India.

I have spent a brilliant 3 days attending this workshop, meeting people and listening to some great talks. The informal format and relatively small size meant there was a real opportunity to interact for the participants.

The topic of the workshop meant that I had a keen professional interest. Listening to the various talks on different computational methods and having sufficient time to discuss with the speakers was great: at the end many of us were thinking of trying other techniques than the ones we usually specialise in. There is a tendency for many to use, popularise and advance a technique they espouse and to usually stick to that one for the most part. It is rare to use several techniques. These 3 days however have convinced me that using the best technique is more important than using “my” technique.

In that very vein, these were the techniques that I enjoyed listening about:
- VOpt method which applies the Variational method (see for example,
- TLM or Transmission Line Matrix method
- Using the scattering approach in the FEM.The speaker, Uday Khankhoje, also spoke about very exciting applications (remote sensing for figuring out surface structures of planetary satellites such as Enceladus)

I am excited about trying some of these methods.

Cheers for now!

By artiagrawal Posted in General

Winter Olympics, Ravel and Science

The title of this post may seem crazy but there is a logic to this madness!

While watching the ice skating event (on TV alas) at the Winter Olympics, I heard presentors talking about the Tovrill and Dean performance (watch at this link) set to the music of Bolero by Ravel.
The routine won the performers a gold medal and they became the highest scoring figure skaters in the world, receiving perfect 6.0 from all judges for artistic impression. The dance is indeed gorgeous.

The music of Bolero however just took my head apart!

To me Bolero is the spirit of Science and hence the title of the post. I am no music expert or afficinado and so I write here about my emotional reaction to this piece. The drums with their regular beat (to me) so beautifully catch the logical and systematic aspect of Science, while the clarinets, tuba and flutes with their whimiscal, dreamy and in turns soaring notes perfectly capture just those aspects about Science. I didnt think that a musical composition could express the nature of Science- to my extreme pleasure and surprise for me Bolero does just that!

Hear it and tell me what you think.


You may think that is a strange title for a post. You are probably right. However I am so excited and satisfied that I could not contain myself and this is the result:

I am working with an experimental partner on Si solar cells. They do the experimental bit and we do the modelling. Now we are starting to get the first set of results and it is immensely satisfying to see our modelling work being correlated to something physically real and measurable. I can’t yet discuss the results here (I will once we publish). As this is one of the first projects for me in which I am working so closely with an experimental partner and for the first time seeing results in a less abstract manner- the sense of satisfaction is magnified. If I had been doing this for 20 years may be it would not be as exciting?

Isn’t Science wonderful?

The PhD crucible

Recently interviewing a PhD candidate brought back memories of my own graduate student days. Specifically the time when I wondered what my PhD meant!

Like many Science students during taught masters and undergraduate courses, one saw the big developments in various fields. It was exciting and inspiring to understand key theories in Physics and the big advances that were made. Names like Gauss, Newton, Feynman, Planck, Boltzman and many others became familiar.

Then came the PhD. The beginning sees a fresh faced and eager candidate hoping to contribute something big to Science. Something like the stuff one was taught in class all these years and there is the desire to add one’s name to the list of distinguished scientists.

But thats not how the PhD seems to proceed!
The stuff one is doing seems so narrow and focused, and you wonder where the big picture is. What is the value of this small piece of work? How will this work ever measure up against the really big developments studied in textbooks?

It takes time to realise that the advances we learned about were made over long periods of time and represent the work of many people. Science can often advance through small increments added up, with each scientist a worthy contributor to the bigger picture. Some make bigger contributions and may become famous. That does not detract from the work of others or the sheer joy everyone can derive from research.

Once you settle this in your head and see where you fit in the larger scheme of things (not completely useless!) it helps! Or at least it helped me find peace in my heart, pride for my work and motivation to keep improving.

A six sided challenge

Hello all!

Recently an idea occured to me and I am looking for someone to work with me on this: the idea is to find the modes of a 6 sided (hexagonal) cavity. If anyone is aware of the solution (published somewheree) please let me know, I would be most grateful.
Otherwise, I want to use the results in a study. Would happily give first authorship of a paper using this result to a collaborator who works out the analytical results and works with me on using these.
I realise this information is sketchy, but I dont know if the idea will work, (hey its research so dont know all the answers). It came to me while going over some notes on Fabry Perot (FP) resonators, that we know the modes and FSR for the FP. How do we get the modes for a differently shaped cavity, analytically?

All thoughts and ideas welcome!


By artiagrawal Posted in General