Nobel Prize in Physics 2018
This collection of research papers, reviews, commentaries and associated content from Nature Research celebrates the 2018 Nobel Prize in Physics for “ground-breaking inventions in the field of laser physics”. Half of the prize has been awarded to Arthur Ashkin for the invention of optical tweezers and their application in biology. The other half has been awarded to Gérard Mourou and Donna Strickland for the invention of the chirped pulse amplification method for generating high-intensity, ultra-short optical pulses which underpins applications such as laser eye surgery, laser fusion and laser particle acceleration. This collection illustrates the breadth, diversity and impact that these optical techniques have had in science.
Optical Tweezer Research
Optically trapping an individual E. coli cell allows the long-term quantification of bacterial swimming phenotype: the stochastic transitions between 'running' and 'tumbling' as well as changes in swimming speed and direction.
Ultrafast force-clamp spectroscopy of single molecules reveals load dependence of myosin working stroke
A dual-trap force-clamp configuration is used to apply a constant load between a binding protein and a single intermittently interacting biological polymer. This allows high-resolution measurements of short-lived molecular complexes and reveals previously undetected complex regulation of the myosin working stroke.
Through shaping of colloidal particles, optical traps with prescribed force–displacement profiles are generated and are used to design a microscopic constant-force spring capable of delivering a constant piconewton-scale restoring force for displacements of several micrometres. Potential future applications include the imaging of sensitive biological membranes.
Quantum state preparation of mesoscopic objects is a powerful tool for the study of physics at the limits. Here, Arita et al. realise the optical trapping of a microgyroscope rotating at MHz rates in vacuum where the coupling between the rotational and translational motion cools the particle to 40 K.
Hybrid systems coupling electron spins and optomechanical responses are of potential use in quantum information systems and sensing technology. Here, the authors demonstrate optical levitation of nanodiamonds and the control of their nitrogen vacancy spins in vacuum.
Nanomechanical sensors that rely on intrinsic resonance frequencies usually present a tradeoff between sensitivity and bandwidth. In this work, the authors realise an optically driven nanorotor featuring high frequency stability and tunability over a large frequency range.
Assembly of higher-order artificial vesicles can unlock new applications. Here, the authors use optical tweezers to construct user-defined 2D and 3D architectures of chemically distinct vesicles and demonstrate inter-vesicle communication and light-enabled compartment merging.
The neural circuits of the vestibular system, which detects gravity and motion, remain incompletely characterised. Here the authors use an optical trap to manipulate otoliths (ear stones) in zebrafish larvae, and elicit corrective tail movements and eye rolling, thus establishing a method for mapping vestibular processing.
Nanoscopy of non-adherent cells is currently not possible, due to their movement in solution. Here the authors immobilize and manipulate fixedE. coli by multiple optical traps; their holographic optical tweezers enable dSTORM imaging of orthogonal planes via 3D realignment of the sample.
Microsources positioned with holographic optical tweezers can establish a highly localized, three-dimensional chemical gradient that allows the manipulation of polarization and migration in single cells.
Single DNA-binding proteins can be tracked on densely covered DNA at high spatial and temporal resolution and in the presence of high protein concentrations by using a technique that combines optical tweezers, confocal fluorescence microscopy and stimulated emission depletion (STED) nanoscopy.
Optical Tweezer Discussion
Since the first discovery of optical gradient and scattering forces in 1970, optical tweezers have helped unveil many mysteries and given deeper insights in many areas of science. Arthur Ashkin, the father of optical tweezers, recalls some 'eureka' moments and shares his viewpoint of the field with Nature Photonics.
Since the discovery of the optical gradient force in 1970 and the first use of laser beams to manipulate microscopic and atomic systems in 1986, optical manipulation has proved to be a versatile optical tool for uncovering mysteries throughout many fields of science.
Optical tweezers have become one of the primary weapons in the arsenal of biophysicists, and have revolutionized the new field of single-molecule biophysics. Today's techniques allow high-resolution experiments on biological macromolecules that were mere pipe dreams only a decade ago.
Using projected light patterns to form virtual electrodes on a photosensitive substrate, optoelectronic tweezers are able to grab and move micro- and nanoscale objects at will, facilitating applications far beyond biology and colloidal science.
Heating due to optical losses in metal nanoparticles, which is usually an unwanted side effect, is harnessed to realize low-power opto-thermoelectric nanotweezers.
Chirped Pulse Amplification Research
Researchers present a waveform synthesis scheme that coherently multiplexes the outputs from two broadband optical parametric chirped-pulse amplifiers. The technique provides control at the sub-cycle scale and generates high-energy ultrashort waveforms for use in strong-field physics experiments.
Based on a passively phase-locked superposition of a dispersive wave and a soliton from two branches of a femtosecond Er-doped fibre laser, researchers demonstrate that single cycles of light can be achieved using existing fibre technology and standard free-space components. The pulses have a pulse duration of 4.3 fs, close to the shortest possible value for a data bit of information transmitted in the near-infrared.
Short laser pulses of femtosecond time scales are in high demand in order to explore the fast electron dynamics in light-matter interactions. Here, the authors demonstrated the compression of free electron laser pulses in the extreme ultraviolet range by using a chirped pulse amplification technique.
A compact source that generates sub-two-cycle-duration pulses with an average power of 0.1 W spanning 6.8–16.4 μm combines the properties of power scalability, high repetition rate and phase coherence for the first time in this spectral region.
Spatially coherent 11.45 nm radiation is produced by outcoupling the harmonics of cavity-enhanced nonlinearly compressed pulses from a Yb-based laser through a pierced cavity mirror. This technique may lead to high-photon-flux ultrashort-pulse extreme-ultraviolet sources for use in a wide range of applications.
The nuclear fusion of hydrogen and boron nuclei has potential advantages over the fusion of deuterium and tritium for energy production as it produces no neutrons. Labaune et al. report progress towards achieving this by colliding a laser-driven particle beam into a laser-generated plasma.
Recently, there has been significant progress on the application of laser-generated proton beams in material science. Here the authors demonstrate the benefit of employing such beams in stress testing different materials by examining their mechanical, optical, electrical, and morphological properties.
Two-photon scanning microscopy is inherently slow and thus limits volumetric calcium imaging. Prevedel et al. achieve increased volumetric imaging speed by tailoring the excitation volume via light sculpting.
Chirped Pulse Amplification Discussion
Ultrafast fibre lasers are an important optical system with industrial, medical and purely scientific applications. Essential components and the operation regimes of ultrafast fibre laser systems are reviewed, as are their use in various applications.
Could massive arrays of thousands of fibre lasers be the driving force behind next-generation particle accelerators? The International Coherent Amplification Network project believes so and is currently performing a feasibility study.
Increasing the power of ultra-high-intensity lasers requires crystal amplifiers and metre-scale optical compression gratings that are ever more difficult to build. Simulations suggest that Raman amplification in a plasma could permit the generation of laser intensities many orders of magnitude higher than currently possible.
The spatiotemporal characterization of a high-peak-power pulsed laser beam reveals previously undetected wavefront distortions.
The Extreme Light Infrastructure (ELI) project is dedicated to the investigation of light–matter interactions at high laser intensities and on short timescales.