2018 – a recap

Six months since my last update! Thought I’d do a quick stream-of-consciousness start-of-the-year recap of what happened for the rest of 2018.


Fast-tracked my Silicon Photonics skills by signing up to Lukas’s fabulous edX course, with a final grade of 98%:


I missed out on the top mark by dropping the ball on some of those early homework questions. How embarrassing.



Dusted off the ol’ pulse-picker (PSIMO Pulse Picker OG8-25-1, which hadn’t been used since about 2008..) and eventually got it to work (a hidden fuse had blown.) This quick video shows me rotating the half waveplate – you can see the pulses being “picked” from 80MHz to ~100Hz. Goodbye thermal effects! Our visiting student Hugo Boiron got some nice preliminary z-scan measurements on gold nanofilms (thanks Hugo!), and more is on the way.

I also drew the official logo for the University of Sydney Early- and Mid- Career Researcher Network (PhysCREAM):


Notice the cream on the shirt and head.


Started developing the new Physics Interdisciplinary Course (Phys3888) with friend and superstar Dr. Ben Fulcher. I’m curating the interdisciplinary laboratory portion of the course, which will include elements of neurophysics and data science. Really looking forward to getting this up and running later this year, I’ll make sure to include more info here as we progress.

I was also invited to the 14th Australia-China Symposium in Changchun – that’s me on the right there.


A delightful trip with many great Australian and Chinese physicists! The facilities there are outstanding.

I gave a few of the third year optics lectures/tutorials with Prof. Martijn de Sterke, and learnt a few things in the process. I look forward to doing more this year. On a related note, I also accepted the offer to teach the Advanced Optics and Photonics honours course with Prof. Ben Eggleton and A/Prof. Stefano Palomba in 2019. So that’s three courses I’ll be heavily involved in this year…

I was the successful recipient of the Research Facilities Access Grant ($3500), to help cover the cost of clean room usage. Thanks also to this contribution, I completed all my clean-room training at the Sydney Nano Research and Prototype Foundry, and started collaborating with Dr. Alvaro Casas Bedoya and Dr. Mortiz Merklein (aka. “Team silicon photonics”) towards developing low-loss silicon waveguides. We’re making good progress, but still some room for improvement – 2019 here we come!


Late last year we finally made our first on-chip plasmonic nano-structures. A lot of design and fabrication effort went into this, but we got there eventually – all as part of Mr. Oliver Bickerton’s honours project. Now that we have this in place, there’s so much that can be done…! Watch this space. And speaking of which, our Oliver Bickerton successfully finished honours year! Congratulations Oliver, thanks for all your hard work.

While this was happening I was working on a couple of papers which…


…both got accepted in the same month.

1) A. Tuniz, H. Schneidewind, J. Dellith, S. Weidlich, and M. A. Schmidtet al., “Nanoapertures without Nanolithography”, ACS Photonics (2018).



Some of the data in this paper was taken just before I left Jena. It took a lot of work to do the modelling and some follow-up experimental characterization, it was worth it – we show a simple way of making metal nanoapertures on a fiber without any kind of lithographic step, and also provide some important guidelines. This work was also presented here at the University of Sydney as part of the Institute of Photonics and Optical Science “Impact Fest”.

2) V. Ng, A. Tuniz, J. Dawes, and C. Martijn de Sterke, “Insights from a systematic study of crosstalk in adiabatic couplers”, OSA Continuum (in production).

This one was just accepted (no hyperlink yet), and comes from a collaboration with our good friends at Macquarie University. This theoretical/numerical work is particularly enjoyable, and we’re learning a lot about adiabatic mode conversion. Even though one of the first papers to look at this topic thoroughly (at least for optical waveguides) was published in 1955, this systematic study shows that there’s still quite a lot to be understood.

It’s the first time I publish in either of these journals (unsurprisingly, also because 2018 was the inaugural year of OSA continuum.)


December also featured Oliver presented his honours work at the AIP congress. Michelle Wang, co-supervised last summer with international media sensation Dr. Birgit Stiller, also presented a poster on Brillouin Plasmonics. Looking forward to working more on this.

Finally I should also mention that, thanks to the successful grant applications of several distinguished colleagues, we have had two amazing pieces of equipment come in this year: the first is the super-fast-and-very-impressive TeraK15 terahertz time-domain-spectroscopy system (its speed and compactness puts our old system to shame), and the other is the neaSNOM microscope, which will finally let us do our own complete near-field characterization of nanophotonic devices. Side by side, these two behemoths give us insane experimental characterization capabilities.

This is by no means an exhaustive summary – other things are happening, with much of it getting lost in the excitement. I’m really looking forward to 2019!

Review paper online!


interfacing-fibers-with-plasmonic-nanoconcentratorsNew invited review paper is online! I wanted to survey the state-of-the-art in fiber plasmonics – for conveniently confining and enhancing light on a fiber tip. As I started working in this field a few years ago, I thought it would have been good to compare systems which, although sharing a platform and an objective, can be quite different from each other. See below!

A. Tuniz and M. A. Schmidt, “Interfacing optical fibers with plasmonic nanoconcentrators”, Nanophotonics 7, 1279–1298 (2018)


Nonlinear fiber plasmonics: new paper in Physical Review Applied


My work on self-recovering long-range surface plasmons in gold-filled optical fibers was recently published in Phys. Rev. Applied! It’s satisfying to see that my original goal of measuring ultrafast nonlinear plasmonic effects on gold nanowires within optical fibers – which formed the crux of my original Humboldt Fellowship to Jena – has come to fruition. Since my original proposal was written in 2014 there has been quite a lot of great work in this field! One of the greatest problems for plasmonic propagation in nanowires in fibers was that, for small wire diameters, the wires break up, and scatter off light at the gaps. As it turns out, if these wires are inside the core of a waveguide (such as an optical fiber), it’s possible to circumvent this, since most of the scattered light is captured by the waveguide, and then immediately fed back into the plasmon! This process is efficient enough to enable measurements of the nonlinearity of gold (via nonlinear absorption) which crucially requires high peak powers to be maintained. Read the article here.

IPOS symposium and SPIE Nanophotonics

Hard to believe the first month of 2018 is nearly over! I thought I might include a couple of photos from two events I attended late last year – the IPOS symposium and the SPIE NanoPhotonics Australasia conference in Melbourne, where I had an invited talk. On the last day I attended the CUDOS Frontiers in Nanoplasmonics Workshop, which featured many distinguished international guests, and was a great opportunity to initiate collaborations. Looking forward to the year ahead (at least, the 11 months left…)

IPOS Symposium, Sydney Nano Institute, University of Sydney
SPIE NanoPhotonics Australasia
SPIE NanoPhotonics Australasia, Swinburne University of Technology, Melbourne

Nerd Nite!

Had a great time last week presenting a new-and-improved talk on invisibility at Nerd Nite! As usual this is a great way to engage with the local community, this time at the legendary Friend in Hand in Glebe just down the road from the University of Sydney. The other speaker at the event was world-famous Prof. Peter Kinderman, who was in Sydney for The Big Anxiety Festival, and gave a beautiful talk about the fundamental role of one’s environment and upbringing on mental health, which in his opinion (from what I understand) overshadows the role of genetics. This appears to be a somewhat controversial view that managed to stir up quite a few audience members.

I recommend keeping an eye out for future Nerd Nite events. I’ll definitely be going back for more!


Science at the local

Last Sunday I had the pleasure of presenting at the Science at the Local event in the Blue Mountains. I’m thankful to Hamish Clarke for the invite up to sunny Springwood – despite the sunny day quite a crowd turned up to the local sports club to hear me talk about The Physics of Invisibility. The audience feedback and engagement was impressive, I had many excellent questions and insightful conversations after the talk- there should be a lot more events like this! The other speaker was Bianca Heng, who discussed the controversial science of video-game addiction – there is much more that needs to be understood, especially in the broader context of the relationship between humans and technology. What a day!

Would highly recommend to keep an eye out on future Science at the Local events – see their facebook page to not miss out.


Auf Wiedersehen IPHT!


The 28th of April was my last official day at the Leibniz Institute for Photonic Technology (IPHT). I consider myself very lucky to have been a part of this incredible group (shown nostalgically in the black-and-white photograph above) led by Prof. Markus A. Schmidt, covering numerous and diverse fields such as plasmonics, non-linear optics, hybrid photonics, metasurfaces and metamaterials, bio-photonics and sensing (and more!) – all within the optical fiber platform. I thank the Alexander von Humboldt Foundation, which sponsored my fellowship and made me feel at home in Germany from the get-go.

I had a very productive and fun two and a half years, making many friends and connections not only inside IPHT, but also in the neighboring Abbe Center of Photonics and the Fraunhofer Institute, as well as the Max Planck Institutes and Center for Molecular Biomedicine – what an environment! Anyone who visits Jena is immediately impressed by the quality of the infrastructure within the City of Light – and I mean that in terms of human, scientific, and educational resources. Of particular note is the Masters in Photonics Program at the Abbe School of Photonics (at which I had the pleasure of lecturing, overseeing student seminars, and superviseing Masters students), which I believe currently provides the best-value English-language photonics education in the world.

Looking back at my two years at IPHT, I produced four first-author publications (with a few more on the way!), contributing four more as co-author, while still contributing to papers with colleagues in Sydney and Freiburg. Fortunately, the experience gained by the group through my contributions has not been lost, and I am confident that the students I recruited and trained will continue with great success in the years to come!

I’ll be officially starting on June 1st at the Australian Institute for Nanoscale Science and Technology, under the University of Sydney Fellowship scheme working on hybrid nonlinear plasmonics with Stefano Palomba and Martijn de Sterke. They’ve been coming up with breakthrough developments and I’m very keen to get started. I learned a lot over the past two years at IPHT, giving me numerous ideas that I intend to pursue in my next position – and beyond.

Thank you IPHT and everyone in Jena – this is my Auf Wiedersehen. I’ll be in touch!

Paper published in the Optical Materials Express Multimaterial and Multifunctional Optical Fibers Feature Issue


Our new paper “Analysis of nanogap-induced spectral blue-shifts of plasmons on fiber-integrated gold, silver and copper nanowires” just appeared in the Optical Materials Express feature issue for “Multimaterial and Multifunctional Optical Fibers”!

Ron Fatobene Ando did a fantastic job in performing a systematic analysis of the origin nano-gaps between the metal and the silica fiber wall, which emerge when filling the nanochannels in photonic crystal fibers and modified step-index fibers with metals. This study was performed for the two canonical plasmonic metals, silver and gold, as well as for copper. By measuring the plasmonic resonances and comparing with simulations, we can obtain an accurate estimate of the nanogap sizes, finding that  they are much smaller than one might expect – we think this effect is due to the interaction of van der Waals and contraction forces at the material interfaces. This will be particularly important for many of the future fiber-plasmonics devices we are designing.

In other news, paper “Excitation of Short-Range Surface-Plasmon Polaritons in a  Gold Nanowire Enhanced Step-Index Fiber” has been accepted as an oral contribution for CLEO Europe, which will be held during the World of Photonics Congress 2017 in the International Congress Centre (ICM Munich, Germany). It will be presented June 27, 2017 at 8.45 in the Mode control session, ROOM 13b.


Back from the CUDOS workshop!


Photo by Alvaro Casas Bedoya

Just returned from a week in Australia, where I had the pleasure of attending the 16th (and final!) CUDOS workshop. This was an opportunity to participate in four days of discussion in a variety of forums such as keynote addresses, research presentations, poster displays and social events from several distinguished speakers – highlights included a keynote talk from Katherine Woodthorpe, and invited talks from Shanhui Fan, Kobus Kuipers, John Sipe and  Alex Szameit, to mention a few. I presented a poster (see below) on our recent work , and met with my future colleagues at the University of Sydney Stefano Palomba, Martijn de Sterke and Guangyuan Li. The laser-tag skirmish event in the Australian bush during the record-setting heat-wave sun was as brutal an affair as one might imagine. The closing gala dinner delivered some emtional moments, as we all reflected on what made CUDOS so succesful, and the legacy it will leave: a combination of synergistic national and international collaborations, the ability to foster researchers both academically and into developing industrial partnerships and start-ups, student outreach, and contirbuting to overall excellence in photonics on a global scale, have created a truly unique research environment which will continue even after CUDOS ends, and which will serve as a model for research centers everywhere.