Photonics |

Minister Penny Simmonds visits the photonics laboratory

Tue, 11 Aug 2026 00:00:00 +1200

Hon Penny Simmonds, Minister of Science, Innovation and Technology and Minister for Tertiary Education, visited the Tuwhiri photonics laboratory at the University of Otago on 11 August 2026.

The visit follows one by her predecessor, Dr Shane Reti, in December 2025, which means both ministers holding the science portfolio during the programme’s first year have now seen the instrument development first hand.

The timing was useful. The programme’s kick-off meeting three weeks earlier had brought the atmospheric science, photonics and engineering teams together to settle what the instrument must achieve, so there was a clearer story to tell than there would have been in the first months of the programme.

JPL meetings and an invited talk in Long Beach

Mon, 27 Jul 2026 00:00:00 +1200

Harald Schwefel visited NASA’s Jet Propulsion Laboratory in Pasadena on 27 July 2026, meeting Andrey Matsko, Subash Khanal and Luis Millán.

JPL matters to Tuwhiri twice over. It is the home of the Aura Microwave Limb Sounder whose record the programme exists to continue, and it is where several of our advisors work on the resonator physics the instrument depends on. Sitting down with people who have operated a limb sounder for two decades is the fastest way to learn which problems are real and which only look hard from the outside.

Subash Khanal is co-applicant on the that formalises this collaboration, so the visit also allowed time for working on that.

The visit coincided with the Optica Advanced Photonics Congress in Long Beach, California, where Harald gave an invited talk at the Nonlinear Photonics topical meeting. Nonlinear Photonics covers exactly the ground the instrument occupies — nonlinear optical materials, frequency conversion and resonator systems — and it is one of the better venues for putting the up-conversion approach in front of the community that would recognise its limits.

Catalyst: Seeding award to build a partnership with NASA JPL

Wed, 01 Jul 2026 00:00:00 +1200

A Catalyst: Seeding project, Bridging CMOS and Photonic Spectroscopy for Stratospheric Water Vapour Measurements, establishes a formal research collaboration between the University of Otago and NASA’s Jet Propulsion Laboratory.

Harald Schwefel is principal investigator, with Dr Subash Khanal of NASA JPL as co-applicant. Annika Seppälä leads the atmospheric science, Mallika Suresh the photonic science, and Randy Pollock the systems engineering. On the JPL side the project also draws on Dr Adrian Tang, who directs JPL’s Space System-on-Chip programme, and Dr Nathaniel Livesey, who led the Aura Microwave Limb Sounder for nearly two decades and sits on Tuwhiri’s advisory board.

Catalyst:Seeding is administered by the Royal Society Te Apārangi on behalf of MBIE. It funds the building of international research relationships rather than the research those relationships go on to produce, which is exactly what is needed here.

Why water vapour

Tuwhiri’s instrument was conceived for ozone. Water vapour is a natural second target: the most abundant greenhouse gas in the atmosphere, closely tied to atmospheric circulation, extreme weather and ozone recovery — and poorly observed in the stratosphere, particularly in the Southern Hemisphere.

The Hunga Tonga–Hunga Haʻapai eruption made the gap plain. It injected an unprecedented quantity of water vapour into the stratosphere, and the observing system was not well placed to track what followed.

Ozone and water vapour sensing share their physical principles but differ in frequency and in what calibration demands. Extending the photonic approach from one to the other is a real piece of work, not a relabelling.

Benchmarking against a proven instrument

Laboratory validation only takes a millimetre-wave spectrometer so far. At some point it has to be measured against an instrument whose behaviour is already understood.

JPL has a compact, flight-proven CMOS spectrometer operating at the 183 GHz water line. The project’s aim over two years is technical alignment — workshops, research exchanges and joint engineering studies — working towards flying the two sensors side by side on a Kea Aerospace Kea Atmos stratospheric aircraft. Measuring the same air at the same moment with a new instrument and an established one is the most credible way to find out what the new one can actually do.

That is a rare opportunity. It also reduces the risk carried by everything Tuwhiri builds afterwards.

Tuwhiri at the EGU General Assembly in Vienna

Fri, 08 May 2026 00:00:00 +1200

Florian Sedlmeir and Hannah Kessenich presented Tuwhiri’s work at the European Geosciences Union General Assembly, held in Vienna from 3 to 8 May 2026.

Florian presented , the instrument side of the programme — how a whispering-gallery-mode resonator converts faint atmospheric signal into optical light that ordinary photonics can measure.

Hannah presented , which addresses the other end of the problem: what you do with the measurements once you have them, and how to describe the behaviour of the ozone hole in terms that a forecasting model can use.

The EGU General Assembly is the largest geosciences meeting in Europe, drawing around 20,000 researchers across the Earth, planetary and space sciences. For a programme that sits between instrument development and atmospheric science, it is a useful place to be heard by both communities at once — and to test whether the case for a low-cost limb sounder lands with the people who would use the data.

Millimeter-Wave Atmospheric Radiometry via Nonlinear Optical Upconversion

Sat, 14 Mar 2026 00:00:00 +1300

Minister Shane Reti visits the photonics laboratory

Wed, 10 Dec 2025 00:00:00 +1300

Dr Shane Reti, then Minister of Science, Innovation and Technology, visited the photonics laboratory at the University of Otago in December 2025.

The visit was a chance to show, rather than describe, what the programme is building: the whispering-gallery-mode resonators at the heart of the instrument, and the up-conversion experiment that turns faint microwave and terahertz signals from the atmosphere into optical light a compact detector can measure.

The argument Tuwhiri makes is partly an economic one — that an instrument small and cheap enough to fly on a CubeSat changes what a country of New Zealand’s size can afford to monitor from space. That case is easier to make standing next to the apparatus.

Visualization and selective manipulation of sub-terahertz whispering gallery modes

Wed, 26 Nov 2025 00:00:00 +1300

Dodd-Walls Centre annual symposium

Mon, 24 Nov 2025 00:00:00 +1300

Mallika Suresh took part in the Dodd-Walls Centre annual symposium, held from 24 to 27 November 2025.

The Dodd-Walls Centre is New Zealand’s Centre of Research Excellence for Photonic and Quantum Technologies, and one of Tuwhiri’s affiliated partners. Its annual symposium puts most of the country’s photonics community in one room, which makes it the natural place to present the up-conversion work and to meet the students the programme will need over the next five years.

Multichannel upconversion of terahertz radiation in an optical disk resonator

Mon, 10 Mar 2025 00:00:00 +1300

Tuwhiri Programme Kick-off Meeting

Mon, 01 Jan 0001 00:00:00 +0000

The occasion

Everyone in the programme in one place for the first time: three research areas, the advisory board, industry partners, and colleagues from Adelaide, Caltech, Earth Sciences New Zealand, Waikato, AUT and the Paihau–Robinson Research Institute.

The welcome function opened with a mihi whakatau, followed by a welcome from Programme Lead Professor Harald Schwefel. Jessa Barder then presented the programme’s new name — Tuwhiri, from the Māori word meaning a clue, or means of discovering something hidden, which is an appropriate metaphor for what an atmospheric sounder does, as well as to reveal or make known, which is an accurate description of the programme’s goals.

Sunday 19 July — Welcome function

Terrace Lounge, University Union Building.

Mihi whakatau, the welcome from the Programme Lead, the presentation of the programme name, and guided tours of the research laboratories.

Monday 20 July — Setting out the problem

Walsh Building.

The morning established why the work matters and where each area currently stands. Annika Seppälä opened on the case for space-based climate and atmosphere monitoring. Mallika Suresh followed on dielectric resonators for nonlinear optical upconversion of microwave signals, and Randy Pollock set out the engineering team’s staffing, status and open questions.

The second session widened the frame: Peter Gibson on climate change projections for New Zealand from CMIP6, Andrey Matsko on microphotonics for spaceborne timing and remote sensing, and Withawat Withayachumnankul on terahertz technology from devices through to sensing and communications.

The afternoon split in two. One workshop took on sensor, platform and data systems integration, chaired by Betina Pavri and Mallika Suresh; the other planned the atmospheric science model simulations, chaired by Annika Seppälä.

The day closed with Jessa Barder on plans for community engagement, a contribution from Richard Querel, and open discussion.

Tuesday 21 July — From requirements to instrument

Centre for Innovation and Mellor Laboratories.

The morning ran from the science down to the hardware. Hamish Lewis presented late-century projections of climate extremes across New Zealand; Florian Sedlmeir on millimetre-wave atmospheric radiometry via nonlinear optical upconversion; Hannah Kessenich on a new diagnostic metric for quantifying Antarctic ozone hole dynamics; John Cater on thermal and mission design; and Betina Pavri on Kea Mk1 interface requirements and environmental test planning.

Two further workshops ran in parallel. The first brought the atmospheric and engineering teams together on instrument requirements for science, chaired by Randy Pollock — the conversation that decides what the instrument has to achieve. The second, chaired by Greg Bodeker, addressed uptake and impact.

A poster session ran over lunch, and Harald Schwefel closed the meeting.