Tag Archives: Andrew Greentree

The palette of the mind

12 July 2017:

Around fifty high performing Year 10 to Year 12 students from Australia and New Zealand came to RMIT on the 11th of July to listen to CNBP Chief Investigator Prof Andy Greentree present  a talk titled “Colour: the palette of the mind.”

The talk was a part of the Youth ANZAAS visit to RMIT University. Youth ANZAAS 2017 is organised by the Australian and New Zealand Association for the Advancement of Science and the Royal Society of New Zealand. It is is an annual residential international forum for science students still at school.

An abstract of Prof Greentree’s talk follows:

Colour is a complicated phenomenon! For most of us, most of the information we receive about the world comes from light, and that light is encoded by colour. This talk will explore colour. From the physics of light, to how we detect colour information, to the psychophysics of how our brain understands those signals to make sense of the world.

Want a better camera? Just copy bees!

4 July 2017:

Check out the latest buzz about bees and their extra light-sensing eyes! CNBP CI Prof Andy Greentree is coauthor on a new paper in PNAS, which identifies how the eyes and brains of honeybees work together, to process colour information.

“If we can design technology to mimic the way bees do this, we’ll be able to create better cameras and image-processing systems for drones and robots,” say the researchers in an article on the science news channel ‘The Conversation‘.

 

Enhancement of the NV quantum yield

3 July 2017:

Researchers from CNBP’s RMIT University node (lead author CNBP PhD student Marco Capelli pictured), have had a paper published in the journal ‘Nanoscale’.

The researchers report an enhancement of the nitrogen-vacancy (NV) quantum yield by up to 7% in bulk diamond caused by an external magnetic field.

The paper is accessible online.

Journal: Nanoscale.

Publication title: Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield .

Authors: M. Capelli, P. Reineck, D. W. M. Lau, A. Orth, J. Jeske, M. W. Doherty, T. Ohshima, A. D. Greentree and B. C. Gibson.

Abstract: The nitrogen-vacancy (NV) centre in diamond is a unique optical defect that is used in many applications today and methods to enhance its fluorescence brightness are highly sought after. We observed experimentally an enhancement of the NV quantum yield by up to 7% in bulk diamond caused by an external magnetic field relative to the field-free case. This observation is rationalised phenomenologically in terms of a magnetic field dependence of the NV excited state triplet-to-singlet transition rate. The theoretical model is in good qualitative agreement with the experimental results at low excitation intensities. Our results significantly contribute to our fundamental understanding of the photophysical properties of the NV defect in diamond.

New Diamond and Nano Carbons conference

1 June 2017:

CNBP was well represented at the 11th International Conference on New Diamond and Nano Carbons, held in Cairns, Australia, 28th May – June 1, 2017.

CNBP Chief Investigator A/Prof Brant Gibson was Co-chair of the conference (pictured) with CNBP researcher Dr Philipp Reineck a contributing speaker, presenting on ‘Bright and photostable nitrogen‐vacancy fluorescence from unprocessed detonation nanodiamonds’.

Also providing a contributing talk was CNBP’s Dr Lindsay Parker, ‘Applications of fluorescent nanodiamonds in cellular molecular tracing.’

Additionally,  CNBP’s Andrew Greentree, Ivan Maksymov, Daniel Drumm, Ashleigh Heffernan, Marco Capelli, Nicole Cordina and Emma Wilson gave poster presentations and Brooke Bacon and Desmond Lau provided administrative and technical support respectively.

The conference spanned research topics from fundamental physical and chemical concepts to applied technologically driven applications with carbon based materials. This including single crystal diamond, nanodiamonds, carbon nanotubes, graphene and other carbon nanostructures.

Synthesis of optical spectra

3 April 2017:

A new publication from CNBP researchers (lead author Dr Ivan Maksymov pictured)  demonstrates a new scheme for synthesis of optical spectra from nonlinear ultrasound harmonics using a hybrid liquid-state and nanoplasmonic device compatible with fibre-optic technology.

The work has just been reported in the journal ‘Optics Express’ and is accessible online.

Journal: Optics Express.

Title: Synthesis of discrete phase-coherent optical spectra from nonlinear ultrasound.

Authors: Ivan S. Maksymov and Andrew D. Greentree.

Abstract: Nonlinear acoustic interactions in liquids are effectively stronger than nonlinear optical interactions in solids. Thus, harnessing these interactions will offer new possibilities in the design of ultra-compact nonlinear photonic devices. We theoretically demonstrate a new scheme for synthesis of optical spectra from nonlinear ultrasound harmonics using a hybrid liquid-state and nanoplasmonic device compatible with fibre-optic technology. The synthesised spectra consist of a set of equally spaced optical Brillouin light scattering modes having a well-defined phase relationship between each other. We suggest that these spectra may be employed as optical frequency combs whose spectral composition may be tuned by controlling the nonlinear acoustic interactions.

Bubbles can detect sound, with light

13 March 2017:

CNBP scientists Dr Ivan Maksymov and Prof Andy Greentree at RMIT University have shown bubbles can detect sound with light in their latest publication in the area of photo-acoustics.

“Bubbles can be a boon for detecting the kind of ultrasound used in medicine as air is less dense than water” explains Dr Ivan Maksymov, “so ultrasound can squeeze a bubble more than the water surrounding it”.

To detect the change in size, Ivan showed that the bubbles could change the amount of light that passed through a gold membrane with nanosized holes in it. “It’s incredible work, I’m really excited by how Ivan has brought together these different kinds of Physics to create something quite new”, said the study’s co-author Prof Andy Greentree.

To detect the effects of sound on the bubble, on light, Ivan had to develop new computational models. The team say that their work may be useful in the development of an optical hydrophone for detecting ultrasound inside the body. “It will give us a new and potentially more sensitive way to ‘see’ with sound” says Ivan.

The work was published in the journal Physical Review A on 13th March 2017 and was funded by the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics.

New paper in ‘Nanoscale’

Low Res Edit 01065 December 2016:

A new publication from CNBP researchers (lead author Philipp Reineck pictured) demonstrates bright and photostable fluorescence from nitrogen-vacancy centers in unprocessed nanodiamond particle aggregates. The work has just been reported in the journal ‘Nanoscale’ and is accessible online.

Journal: Nanoscale.

Title: Bright and photostable nitrogen-vacancy fluorescence from unprocessed detonation nanodiamond.

Authors: P. Reineck, M. Capelli, D. W. M. Lau, J. Jeske, M. R. Field, T. Ohshim, A. D. Greentree and B. C. Gibson.

Abstract: Bright and photostable fluorescence from nitrogen-vacancy (NV) centers is demonstrated in unprocessed detonation nanodiamond particle aggregates. The optical properties of these particles is analyzed using confocal fluorescence microscopy and spectroscopy, time resolved fluorescence decay measurements, and optically detected magnetic resonance experiments. Two particle populations with distinct optical properties are identified and compared to high-pressure high-temperature (HPHT) fluorescent
nanodiamonds. We find that the brightness of one detonation nanodiamond particle population is on the same order as that of highly processed fluorescent 100 nm HPHT nanodiamonds. Our results may open the path to a simple and up-scalable route for
the production of fluorescent NV nanodiamonds for use in bioimaging applications.

Education session at Olympus Australia

Andy-Greentree-at-Olympus26 August 2016:

Olympus LIVE hosted a workshop today, involving a group of Quantum Physics researchers and  students from RMIT University and the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP).

It was the first microscopy workshop of its kind involving Olympus, the University and Centre, giving students valuable exposure and hands-on experience with resident Olympus microscopy experts.

The initial planning for the event was coordinated by CNBP Chief Investigator Prof Andrew Greentree from RMIT University (pictured top left) and CNBP industry partner Mr Jian Shen from Olympus Australia. The day consisted of a training/education session that was part of the ‘Masters in Nanotechnology and Smart Materials’ course, which is in its first year at RMIT University.

The event was hosted by Olympus at their state of the art new facility at Notting Hill, Melbourne and included a theory session, hands on training on microscopes run by Olympus experts, and a tour of some of the facilities.

It is planned that this will become an annual event as part of the ‘Masters in Nanotechnology and Smart Materials’ course at RMIT.

Said Prof Greentree, “This is just another way that the Olympus/CNBP partnership is providing benefits above and beyond that of direct research.”

 

Inaugural Professorial Lecture by CI Greentree

Andy-Greentree_web19 August 2016:

CNBP Chief Investigator Andrew Greentree presented to a full-house at RMIT University during his Inaugural Professorial Lecture on Friday evening, August 19th, 2016.

Over 150 colleagues, friends, family and members of the public were in attendance to hear about Andy’s innovative research, and to better understand the exciting potential of quantum technology and its many applications.

The inspiring 60 minute talk included live light-based demonstrations and a Q&A session with the audience giving Andy a heartfelt ovation as proceedings concluded. Informal feedback from guests as they departed was that the talk had been inspiring, educational and thoroughly enjoyable in nature!

Below – images from the event.

Andy-Professorial (1)

Andy-Professorial2

CNBP visits Belmont High School

Outreach-1ab13 November 2015:

CNBP researchers Andy Greentree, Denitza Denkova and Lindsay Parker took their science to the students on Friday Nov 13th, visiting Belmont High School for a fun filled day of outreach, incorporating science demonstrations, talks, informal discussion and chat.

First up was a 75 minute stage show in front of approximately 80 students from Years 8 and Year 9. Light as a concept was first explained, its wave and particle nature providing the basis for the session. A leaf-blower, table tennis balls, lasers, strobe lights and running water were also used, demonstrating the nature of light and its reflective, refractive and diffractive properties.

Nanodiamonds, iPhones, invisibility cloaks and glow sticks also made an appearance with the challenges and opportunities of looking deeply into the body and CNBP’s research mission clearly outlined.

This was followed by morning tea with the teaching staff and then a further talk and Q&A session with the school’s Year 12 chemistry class.

Thank you to all the students and teachers involved on the day. Great fun and extremely rewarding!