Experiments – Research and outreach abroad

I made it to Calgary. It was a fantastic road trip. The last few days of it were spent between mountains, lakes and my laptop, enjoying the views and preparing a presentation for a seminar at the University of Calgary for its Optics and Photonics Society (COPSS) . COPSS are excellent hosts, and all pictures herein at courtesy of Linhui Yu.

My talk was on my research and life as a PhD student in the University of Southampton’s Optoelectronics Research Centre. The audience was really engaging, and had lots of questions for me. We talked about my experience as a student in Southampton, and I presented some of the work that I’ve done as President of Southampton’s Optics and Photonics Society.

Presenting my work on integrated polarising couplers.

I run a small workshop using the outreach kit that I am travelling with. Part of the kit features samples to explain the research that we do in Southampton, that are made with the fabrication tools that are available in Southampton. In this picture I am talking about a hollow-core fibre preform that was 3D printed by Lieke van Putten as part of her PhD research.

Demonstrating examples of kit that I use to teach about optoelectronics science and research. I'm holding a 3D printed hollow-core fibre preform made by Lieke Van Putten. — Demonstrating examples of kit that I use to teach about optoelectronics science and research. I’m holding a 3D printed hollow-core fibre preform made by Lieke Van Putten.

I had the chance to visit research labs. There’s some really cool work going on in the Electrical Engineering department for developing new systems for the optical imaging of the brain.

I also visited 3 labs in the physics departments, where they were doing some mind-blowing quantum physics experiments, including, but not limited to, magneto-optical trapping (Alexander Lvosky, and team), quantum repeaters for long-haul telecommunications systems (Wolfgang Tittel, and team), and nanoscale optomechanics (Paul Barclay, and team).

A big thanks to Chris Healey for facilitating my visit through the physics department.

Finally, a bit of science. I really like this picture. It was taken through diffraction glasses. These are sheets of plastic with 1000s of parallel lines that split all of the colours of light by diffraction. I’ve handed out hundreds of these glasses in science fairs, exhibitions, garden shows, etc. and people love them! They are really useful to grab people’s attention and serve as a great ice-breaker at the start of any conversation.

Life is colourful if you look at it through diffraction glasses!

Eureka. I made an experiment, and then made it better.

In my PhD I am building integrated optical circuits. The devices I have been making act as polarising filters: they split a light signal into 2 signals that have different amounts of polarisation in each of them. It’s a bit like with polarised sunglasses, where held one way (say horizontally) the light coming through looks strong, and when turned at a right angle, the light looks weak. My devices have the same effect, and I want to quantify this contrast in the strengths of the polarised light with physical quantities.

So this is how I did it

Integrated photonics experiments are delicate — My integrated photonics experiment

Now the tricky thing with this experiment is that am trying to measure the polarisation contrast within a tiny ray of light that is very close to a huge sun that is a source of unwanted noise. The higher the noise the harder it is to measure a high level of polarisation contrast at the device output. It works on a scale of 1 to 100 (in dBs for those familiar with logarithmic scales). Said differently, without taking care, my device looks like it’s on level 5. If I collect the data by filtering out the noise then I can show a higher level of contrast. I used a combination of fibre optics, microscope objectives, highly precise mechanical stages and filters to try and make it better.

It’s a bit like playing Pokemon. I was at level 17 initially, worked hard to improve an experiment and after some time got to level 28. That’s a 10 billion (10^10!) fold improvement in contrast. Next step is level 30; at that point my device evolves from a research product to a device worthy of industrial interest.

Tag: Experiments

Meeting the COPSS

Integrated Photonics Research