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Bio‐enabled and bio‐mimetic nanomaterials represent functional materials, which use bio‐derived materials and synthetic components to bring the better of two, natural and synthetic, worlds. Prospective broad applications are flexibility and mechanical strength of lightweight structures, adaptive photonic functions and chiroptical activity, ambient processing and sustainability, and potential scalability along with broad sensing/communication abilities. Here, we summarize recent results on relevant functional photonic materials with responsive behavior under mechanical stresses, magnetic field, and changing chemical environment. We focus on recent achievements and trends in tuning optical materials' properties such as light scattering, absorption and reflection, light emission, structural colors, optical birefringence, linear and circular polarization for prospective applications in biosensing, optical communication, optical encoding, fast actuation, biomedical fields, and tunable optical appearance. Introduction of stimuli‐responsive and/or functional materials into bio‐inspired materials and structures enables that of materials and structures to act as multi‐functional photonic devices such as switchable colorimetric adhesives, multi‐logic value bio‐computing, and colorimetric stress/strain sensor.

Graphene is a single-layer crystal of carbon, the thinnest two-dimensional material. It has unique electronic and photonic properties.

Holographic telepresence demonstrated A practical method of producing truly three-dimensional images that do not require the viewer to wear special eyewear would have many potential applications - in telemedicine, mapping and entertainment, for instance. True 3D holographic displays have so far lacked the capability of updating images with sufficient speed to convey movement. Now, a team working at the University of Arizona's College of Optical Sciences and Nitto Denko Technical Corporation in Oceanside, California, has developed a system that updates images at close to real-time. In a proof-of-concept experiment, they adapt an established technique based on holographic stereographic recording and a novel photorefractive polymeric material as the recording medium to produce a holographic display that can refresh its images every two seconds. Multicoloured and full parallax display are possible in this system - as is 3D 'telepresence', in which data describing holographic images from one location are transmitted to another location where the images are 'printed' with the quasi-real time dynamic holographic display. Holographic displays can produce truly three-dimensional (3D) images, but have so far been unable to update images fast enough. These authors have adapted a previous technique, based on holographic stereographic recording with a photorefractive polymeric material as the recording medium, to produce a quasi-real-time holographic display that can refresh its images every two seconds, and use it to demonstrate the possibility of 3D telepresence. Improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment. Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms 1 and the absence of large-area and dynamically updatable holographic recording media 2 have prevented realization of the concept. Here we use a holographic stereographic technique 3 and a photorefractive polymer material as the recording medium 4 to demonstrate a holographic display that can refresh images every two seconds. A 50 Hz nanosecond pulsed laser is used to write the holographic pixels 5 . Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.

Nanoscale quantum emitters are key elements in quantum optics and sensing. However, efficient optical excitation and detection of such emitters involves large solid angles because their interaction with freely propagating light is omnidirectional. Here, we present unidirectional emission of a single emitter by coupling to a nanofabricated Yagi-Uda antenna. A quantum dot is placed in the near field of the antenna so that it drives the resonant feed element of the antenna. The resulting quantum-dot luminescence is strongly polarized and highly directed into a narrow forward angular cone. The directionality of the quantum dot can be controlled by tuning the antenna dimensions. Our results show the potential of optical antennas to communicate energy to, from, and between nano-emitters.

Covers the fundamental science of grinding and polishing by examining the chemical and mechanical interactions over many scale lengths Manufacturing next generation optics has been, and will continue to be, enablers for enhancing the performance of advanced laser, imaging, and spectroscopy systems.

Nanocrystal quantum dots have favourable light-emitting properties. They show photoluminescence with high quantum yields, and their emission colours depend on the nanocrystal size—owing to the quantum-confinement effect—and are therefore tunable. However, nanocrystals are difficult to use in optical amplification and lasing. Because of an almost exact balance between absorption and stimulated emission in nanoparticles excited with single electron–hole pairs (excitons), optical gain can only occur in nanocrystals that contain at least two excitons. A complication associated with this multiexcitonic nature of light amplification is fast optical-gain decay induced by non-radiative Auger recombination, a process in which one exciton recombines by transferring its energy to another. Here we demonstrate a practical approach for obtaining optical gain in the single-exciton regime that eliminates the problem of Auger decay. Specifically, we develop core/shell hetero-nanocrystals engineered in such a way as to spatially separate electrons and holes between the core and the shell (type-II heterostructures). The resulting imbalance between negative and positive charges produces a strong local electric field, which induces a giant (∼100 meV or greater) transient Stark shift of the absorption spectrum with respect to the luminescence line of singly excited nanocrystals. This effect breaks the exact balance between absorption and stimulated emission, and allows us to demonstrate optical amplification due to single excitons. Nanocrystals for lasers Semiconductor nanocrystals have very good light-emitting properties, so have potential as optical amplification media that can be easily processed with solution-based techniques: possible applications include optical interconnects in microelectronics, lab-on-a-chip technologies and quantum information processing. The problem with these structures is that at least two excitons (bound electron–hole pairs) need to be present in a nanocrystal before optical gain can be achieved, and this limits performance. In effect, the excitons annihilate each other before optical amplification can occur. This obstacle has now been overcome using nanocrystals with cores and shells made from different semiconductor materials, constructed in such a way that electrons and holes are separated from each other. This makes optical gain based on single excitons possible, significantly enhancing their promise as a practical optical material for laser applications. Semiconductor nanocrystals seem good candidates for 'soft' optical gain media, but optical gain and lasing is hard to achieve owing to a fundamental optical effect, which involves the problem that at least two excitons need to be present in a nanocrystal to achieve gain, and this limits performance. Here the problem is circumvented by designing nanocrystals with cores and shells made from different semiconductor materials, and in such a way that electrons and holes are separated from each other: this makes possible optical gain based on single excitons, thereby significantly enhancing the promise of semiconductor nanocrystals as practical optical materials for a wide range of lasing applications.

Carbon nanotubes possess unique properties that make them potentially useful in many applications in optoelectronics. This review describes the fundamental optical behaviour of carbon nanotubes as well as their opportunities for light generation and detection, and photovoltaic energy generation. Carbon nanotubes (CNTs) are nearly ideal one-dimensional (1D) systems, with diameters of only 1–3 nm and lengths that can be on the scale of centimetres. Depending on the arrangement of the carbon-atom honeycomb structure with respect to their axis, CNTs can be direct bandgap semiconductors, or metals with nearly ballistic conduction. The excited states of semiconducting CNTs can be produced by either optical or electrical means and form strongly bound (with dissociation energies of around 0.5 eV), luminescent, 1D excitons. The single-atomic-layer structure makes the optical properties of CNTs especially sensitive to their environment and external fields, and this can be used to tune them. Here we review the nature and properties of CNT excited states, the optical and electrical mechanisms of their production, their radiative and non-radiative modes of decay, the role of external electric fields, and their possible technological use as nanometre-scale light sources, photodetectors and photovoltaic devices.

Photonic integrated circuits (PIC) can be mass-produced by 3D-printing technologies in combination with advanced hybrid inorganic–organic materials. In this work we present the development of hybrid inorganic–organic materials based on the fast sol–gel process (FSG) which can be used as a “tool kit” for the fabrication of advanced optical materials. We present routes to fabrication of FSG materials with a variety of properties: the materials may exhibit mechanical toughness or be elastic; they may be thermally and UV-curable, they can have a tailored refractive index value and tailored chemical environment, such as an aromatic matrix. Using these materials, we demonstrated strong optical bonding between optical components for solar energy and optical fiber coupler systems. We demonstrated fabrication of macroscale optical elements by 3D-printing methods, such as soft lithography, inkjet, and digital light processing (DLP) printing. We also demonstrated 3D-printing fabrication of nano/microscale optical elements by soft lithography, nanoimprint lithography (NIL), and direct laser writing (DLW). The obtained 3D-printed sol–gel optical elements were found to exhibit mechanical advantages: improved surface quality, resistance to solvents, improved adhesion to glass substrate and stability to temperature above 200 °C compared with 3D-printed organic polymer elements. In addition, the sol–gel elements present the following optical advantages: improved optical quality, improved optical transmission, and durability to laser radiation. We believe that this class of materials is a promising candidate for use in mass production of photonic integrated circuits (PIC) by 3D-printing technologies. UV-curable fast sol–gel (FSG) bonding and 3D printing (a) Bonding of a BK7 glass prism to a silicon-based wafer by UV curing of FSG material, where the FSG is applied in the interface between them. (b) Macroscale “cubic” shaped optical element printed by 3D Digital light processing (DLP). Highlights Hybrid glassy materials with long shelf life were developed using the fast sol–gel process. The process is a tool kit for fabrication of thermal/UV-curable resists with tailored properties. Demonstration of optical bonding of components for solar energy and optical fiber coupler systems. Demonstration of macroscale optical elements by 3D printing with inkjet and DLP printing. Demonstration of microscale optical elements by 3D printing with NIL and DLW printing.