Day 2: Quantum Bio-Photonics Incubator
Maria Solyanik, The George Washington University
Participants of the Quantum Bio-Photonics Incubator started to arrive to the OSA headquarters early in the morning to make the best of the second and final day of the event. Most of the members feel comfortable addressing each other by names instead of formal titles, degrees and surnames. General level discussions of the research projects and formal introductions, which dominated the environment the morning before, have been replaced by handshakes, friendly smiles and greetings, followed by detailed questions about theoretical approaches, availability of experimental setups and data. "We came up with reasonably impossible experiments yesterday!" remarked Graham Fleming when greeting Niek van Hultz in the conference room. "Yes, we still should think more outside the box" was Niek's response.
Attendees of the Quantum Bio-Photonics Incubator gather at the start of the second day of the meeting
Last evening’s discussions have been smoothly picked up this morning. "How can one use strong correlations in entangled light sources in spectroscopy?" asked Frank Schlawin (University of Oxford, UK) the day before. His research on two-photon absorption reveals a possibility of frequency discrimination accessible only in quantum light experiments. Applications of this research direction, such as coincidence counting detectors and the experimental realization of an entangled two-photon scanning microscope, were discussed by Ted Goodson, University of Michigan, USA. The latter application is an already patented technology. The time and space-resolved propagation of collective modes such as excitons in organic materials, and ways to extract detailed level structure of complicated molecules, are some of the goals that speakers highlighted yesterday. One unanswered questions raised was: "is there something between atoms and proteins that could be a toy-model to consider on the path to understanding biological samples?" This question has been answered today. According to Alex Liddle, it is possible to exploit modern nanofabrication techniques to arrange fluorophores in a way to get increasingly complicated protein-like structures.
In order to understand photosynthesis and get efficient experimental prototypes of a man-made photosynthetic system, one still need to address a number of problems. Ivan Kassal, University of Sydney, Australia, brought up the topic of sunlight coherence in natural photosynthesis. In particular, he stressed the role of spectral coherence in light harvesting. He linked efficiency to the internal structure of the sample and coherence properties of sunlight using Förster resonance energy transfer. An outside-the-box idea was proposed by Marcelo Davanco, NIST, USA. He suggested using his technique of measuring the quantum efficiency of InGaAs/GaAs quantum dots, imbedded in a micrometer-scale Bragg grating bullseye cavity, for similar experiments with biological samples. The modeling of photosynthesis inspired Sara Nunez-Sanchez, University of Vigo, Spain, to explore the idea of mimicking this process in order to manipulate and guide light in molecular materials. Her group revealed metallic properties such as the generation of surface polariton modes in J-aggregate films.
Above Sara Nuñez-Sanchez, Alex Liddle and Ivan Kassal share their insights into the field during a discussion moderated by host Greg Engel
A unique way to access the internal properties of cells, such as their detailed structure and enzyme dynamics, can be accomplished by using nanosensors, as was discussed by Frank Vollmer, University of Exeter, UK. These sensors have a capability to detect individual ions in biological structures due to the coupling of emitted photons to whispering gallery modes in glass microspheres, which are used as resonators. A few more conventional tools available for probing biological samples include scanning tunneling microscopy, scanning near-field optical microscopy, and atomic force microscopy. According to Santiago Solares, The George Washington University, USA, they allow atomic resolution of protein structures (solid and liquid substrates, as well as measurements in vacuum), give access to molecular mechanics, surface topology, response to mechanical stress, and electrical properties.
The Incubator has encompassed a variety of novel results and existing problems in quantum bio-photonics: spectroscopy with ultra-fast, squeezed, quantum and classical light sources; plasmon, polariton and soliton energy and charge transfer; non-linear processes induced by quantum light; efficient photosynthetic reactions and light harvesting, and much more. As the curtain closes, the group discussed the experimental and theoretical work that still needs to be done. "Every theory should yield a testable prediction, and every experiment should test a prediction", says host Greg Engel, The University of Chicago, USA. It was concluded that smaller systems that are not highly symmetric are desirable and spectroscopically addressable. Time-resolved chiral spectroscopy, X-ray and NMR techniques are potential avenues for development as well.
The buzz word of this decade, quantum, has been the main focus of the Quantum Bio-Photonics Incubator. The incubator was a great opportunity to unite quantum optics, chemistry and molecular spectroscopy in a way to creatively advance the field of bio-photonics. It will continue to have impact as progress is made with exciting technologies such as as artificial photosynthesis, biomechanical computing, chemical information processing, single photon bio-sensing, and biochemical energy sources. As Elizabeth Rogan, CEO of The Optical Society mentioned in her opening remarks yesterday, the USA allocated $1.3 billion of funding towards the National Quantum Initiative. Therefore, we can be confident that quantum bio-photonics has great prospects and one day may change the world in the same way as such fruitful fields as semiconductor physics, laser science and genetics did.
