Nonlinear optics is the study of the interaction of intense laser light with matter. This Third Edition has been rewritten to conform to the standard SI system of units and includes comprehensively ...updated material on the latest developments in the field. The book introduces the entire field of optical physics and specifically the area of nonlinear optics. It focuses on the fundamental issues including the electromagnetic origin of optical phenomena, the quantum mechanical description of the optical properties of matter, the role of spatial symmetries in determining the optical response, causality and Kramers Kronig relations, and ultrafast and high intensity optical effects.
Nonlinear optical phenomena are crucial for a broad range of applications, such as microscopy, all-optical data processing, and quantum information. However, materials usually exhibit a weak optical ...nonlinearity even under intense coherent illumination. We report that indium tin oxide can acquire an ultrafast and large intensity-dependent refractive index in the region of the spectrum where the real part of its permittivity vanishes. We observe a change in the real part of the refractive index of 0.72 ± 0.025, corresponding to 170% of the linear refractive index. This change in refractive index is reversible with a recovery time of about 360 femtoseconds. Our results offer the possibility of designing material structures with large ultrafast nonlinearity for applications in nanophotonics.
An introduction to ghost imaging: quantum and classical Padgett, Miles J.; Boyd, Robert W.
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
08/2017, Letnik:
375, Številka:
2099
Journal Article
Recenzirano
Odprti dostop
Ghost imaging has been a subject of interest to the quantum optics community for the past 20 years. Initially seen as manifestation of quantum spookiness, it is now recognized as being implementable ...in both single- and many-photon number regimes. Beyond its scientific curiosity, it is now feeding novel imaging modalities potentially offering performance attributes that traditional approaches cannot match.
This article is part of the themed issue ‘Quantum technology for the 21st century’.
Classical entanglement? Karimi, Ebrahim; Boyd, Robert W.
Science (American Association for the Advancement of Science),
12/2015, Letnik:
350, Številka:
6265
Journal Article
Recenzirano
Entanglement is a property of the quantum world; classical systems need not apply
Since the inception of quantum theory, scientists and philosophers have been puzzled by the apparent indeterminacy of ...physical properties prior to the measurement process. These problems suggest that quantum mechanics might ultimately be incompatible with basic notions of “realism”—that is, the view that a physical system possesses inherent properties that are independent of procedures used to measure them. This issue lies at the core of the famous gedanken experiment of Einstein, Podolsky, and Rosen (EPR) (
1
) and of attempts to develop a conceptual understanding (
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–
4
) of EPR correlations.
Orbital angular momentum (OAM) of light is an attractive degree of freedom for fundamental studies in quantum mechanics. In addition, the discrete unbounded state-space of OAM has been used to ...enhance classical and quantum communications. Unambiguous measurement of OAM is a key part of all such experiments. However, state-of-the-art methods for separating single photons carrying a large number of different OAM values are limited to a theoretical separation efficiency of about 77%. Here we demonstrate a method which uses a series of unitary optical transformations to enable the measurement of light's OAM with an experimental separation efficiency of >92%. Furthermore, we demonstrate the separation of modes in the angular position basis, which is mutually unbiased with respect to the OAM basis. The high degree of certainty achieved by our method makes it particularly attractive for enhancing the information capacity of multi-level quantum cryptography systems.
We critically analyze reported measured values of the third-order nonlinear optical susceptibility χ(3) of bulk gold. Reported values of this quantity span a range of more than three orders of ...magnitude. Much of this variation results from the use of different measurement procedures which are sensitive to different contributions to the nonlinear optical response. For example, values measured through use of third-harmonic generation or non-degenerate four-wave mixing tend to be significantly lower than those obtained from measurements of the intensity-dependent refractive index. We ascribe this behavior to the fact that the first two processes respond only to “instantaneous” nonlinearities, whereas the nonlinear refractive index has a contribution from the much stronger but much slower “hot electron,” or “Fermi-smearing” mechanism, which has a response time of the order of picoseconds. The data also reveal that the hot-electron contribution has a strong dependence on laser wavelength, because of the turn-on of the 5d to 6sp transition at about 550nm. It is hoped that the compilation presented here will prove useful in establishing what value of χ(3) is most appropriate for adoption under various laboratory conditions.
Ultraslow waves on the nanoscale Tsakmakidis, Kosmas L.; Hess, Ortwin; Boyd, Robert W. ...
Science (American Association for the Advancement of Science),
10/2017, Letnik:
358, Številka:
6361
Journal Article
Recenzirano
Odprti dostop
There has recently been a surge of interest in the physics and applications of broadband ultraslow waves in nanoscale structures operating below the diffraction limit. They range from light waves or ...surface plasmons in nanoplasmonic devices to sound waves in acoustic-metamaterial waveguides, as well as fermions and phonon polaritons in graphene and van der Waals crystals and heterostructures. We review the underlying physics of these structures, which upend traditional wave-slowing approaches based on resonances or on periodic configurations above the diffraction limit. Light can now be tightly focused on the nanoscale at intensities up to ~1000 times larger than the output of incumbent near-field scanning optical microscopes, while exhibiting greatly boosted density of states and strong wave-matter interactions. We elucidate the general methodology by which broadband and, simultaneously, large wave decelerations, well below the diffraction limit, can be obtained in the above interdisciplinary fields. We also highlight a range of applications for renewable energy, biosensing, quantum optics, high-density magnetic data storage, and nanoscale chemical mapping.
Observation of optical polarization Möbius strips Bauer, Thomas; Banzer, Peter; Karimi, Ebrahim ...
Science (American Association for the Advancement of Science),
02/2015, Letnik:
347, Številka:
6225
Journal Article
Recenzirano
Möbius strips are three-dimensional geometrical structures, fascinating for their peculiar property of being surfaces with only one "side"—or, more technically, being "nonorientable" surfaces. ...Despite being easily realized artificially, the spontaneous emergence of these structures in nature is exceedingly rare. Here, we generate Möbius strips of optical polarization by tightly focusing the light beam emerging from a q-plate, a liquid crystal device that modifies the polarization of light in a space-variant manner. Using a recently developed method for the three-dimensional nanotomography of optical vector fields, we fully reconstruct the light polarization structure in the focal region, confirming the appearance of Möbius polarization structures. The preparation of such structured light modes may be important for complex light beam engineering and optical micro- and nanofabrication.
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