| 1. |
- Cai, Fuhong, et al.
(author)
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Use of tunable second-harmonic signal from KNbO3 nanoneedles to find optimal wavelength for deep-tissue imaging
- 2014
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In: Laser & Photonics reviews. - : Wiley. - 1863-8880 .- 1863-8899. ; 8:6, s. 865-874
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Journal article (peer-reviewed)abstract
- Nonlinear optical (NLO) responses of perovskite-type nanostructures have a variety of potential applications owing to the highly efficient frequency conversion guaranteed by both the material itself and the nanometer-scale configuration. KNbO3 (KN) nanoneedles have been identified as a promising NLO material because of the superior broadband frequency conversion efficiency, and if incident light is propagating in a direction perpendicular to the axis of a nanoneedle, then the phase-matching constraint can be relaxed. Here, the second-harmonic generation (SHG) and third-harmonic generation (THG) responses of both individual and clustered KN nanoneedles are reported. Based on these results, a novel method is proposed for determining the optimal excitation wavelength for NLO imaging of several biological samples, with KN nanoneedles acting as NLO agents. The method is shown to provide the optical features in the focal plane and a more reliable estimation of the optimal excitation wavelength for deep-tissue imaging.
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| 2. |
- Ding, Fei, et al.
(author)
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Ultrabroadband strong light absorption based on thin multilayered metamaterials
- 2014
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In: Laser & Photonics reviews. - : Wiley. - 1863-8880 .- 1863-8899. ; 8:6, s. 946-953
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Journal article (peer-reviewed)abstract
- Light absorbers have drawn intensive attention as crucial components for solar-energy harvesting, thermal emission tailoring, modulators, etc. However, achievement of light absorbers with wide bandwidth remains a challenge thus far. Here, a thin, unprecedentedly ultrabroadband strong light absorber is proposed and experimentally demonstrated, which consists of periodic taper arrays constructed by an alumina-chrome multilayered metamaterial (MM) on a gold substrate. This MM can change from a hyperbolic material to an anisotropic dielectric material at different frequency ranges and the special material features are the fundamental origins of the ultrabroadband absorption. The absorber is quite insensitive to the incident angle, and can be insensitive to the polarization. One two-dimensional periodic array of 400-nm height MM tapers is fabricated. The measured absorption is over 90% over almost the entire solar spectrum, reaching an average level of 96%, and remains high (above 85%) even in the longer-wavelength range till 4 m. The proposed absorbers open up a new avenue to realize broadband thin light-harvesting structures.
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| 3. |
- Lin, Jiao, et al.
(author)
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A nano-plasmonic chip for simultaneous sensing with dual-resonance surface-enhanced Raman scattering and localized surface plasmon resonance
- 2014
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In: Laser & Photonics reviews. - : Wiley. - 1863-8880 .- 1863-8899. ; 8:4, s. 610-616
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Journal article (peer-reviewed)abstract
- A dual-resonance surface-enhanced Raman scattering (SERS) chip which also serves as a localized surface plasmon resonance (LSPR) refractive index sensor is proposed. The dual-resonance SERS chip can simultaneously enhance excitation and Stokes lines for Raman signals detection in a broad wavelength region with virtually no limitation. Thus, it is especially useful for Raman detection at long wave numbers and hyper Raman. The great performance of this chip relies on the highly independent tunability of the two localized plasmonic resonances from the optical to the nearinfrared region and the strict "hot spot" match in space for both resonant wavelengths. Furthermore, Raman signals of polymethyl-methacrylate (PMMA) from 500 cm(-1) to 3300 cm(-1) are measured in the experiments and an obvious superiority can be seen compared to a single-resonance SERS chip. In an addition, by using the subradiant magnetic dipole resonance, the LSPR refractive sensor gives a high sensitivity of 577 nm/RIU and high figure of merit (FoM) of 14.2. The experimental results are consistent with the simulated results. This dual-functional sensing chip opens a route for dual-modality detection of the concentration of some specific molecules.
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| 4. |
- Tittel, Wolfgang, et al.
(author)
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Photon-echo quantum memory in solid state systems
- 2010
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In: Laser & Photonics Reviews. - : Wiley. - 1863-8880 .- 1863-8899. ; 4:2, s. 244-267
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Research review (peer-reviewed)abstract
- Many applications of quantum communication crucially depend oil reversible transfer of quantum states between light and matter Motivated by rapid recent developments in theory and experiment, we review research related to quantum memory based oil a photon-echo approach in solid state material with emphasis on use in a quantum repeater After introducing quantum communication, the quantum repeater concept. and properties of a quantum memory required to be useful in a quantum repeater, we describe the historical development from spin echoes, discovered in 1950. to photon-echo quantum memory We present a simple theoretical description of the ideal protocol, and comment oil the impact of a non-ideal realization Oil Its quantum nature We extensively discuss rare-earth-ion doped crystals and glasses as material candidates, elaborate oil traditional photon-echo experiments as a test-bed for quantum State storage, and describe the current state-of-the-art of photon-echo quantum memory Finally, we give a brief outlook On Current research.
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| 5. |
- Torres Company, Victor, 1981, et al.
(author)
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Optical frequency comb technology for ultra-broadband radio-frequency photonics
- 2014
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In: Laser and Photonics Reviews. - : Wiley. - 1863-8899 .- 1863-8880. ; 8:3, s. 368-393
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Research review (peer-reviewed)abstract
- The outstanding phase-noise performance of optical frequency combs has led to a revolution in optical synthesis and metrology, covering a myriad of applications, from molecular spectroscopy to laser ranging and optical communications. However, the ideal characteristics of an optical frequency comb are application dependent. In this review, the different techniques for the generation and processing of high-repetition-rate (>10GHz) optical frequency combs with technologies compatible with optical communication equipment are covered. Particular emphasis is put on the benefits and prospects of this technology in the general field of radio-frequency photonics, including applications in high-performance microwave photonic filtering, ultra-broadband coherent communications, and radio-frequency arbitrary waveform generation.
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| 6. |
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| 7. |
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| 8. |
- Svanberg, Sune
(author)
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Gas in scattering media absorption spectroscopy - from basic studies to biomedical applications
- 2013
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In: Laser & Photonics Reviews. - : Wiley. - 1863-8880. ; 7:5, s. 779-796
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Research review (peer-reviewed)abstract
- The recently introduced Gas in Scattering Media Absorption Spectroscopy (GASMAS) technique provides novel possibilities for analysis in biophotonics. Free gas in pores or cavities is monitored with narrow-band laser radiation, which can discern the gas absorptive imprints which are typically several orders of magnitude more narrow than the features of the surrounding tissue through which the diffusely scattered light emerges to the detector. Important gases monitored are oxygen and water vapour. Applications include diagnosis of human sinus cavities and surveillance of neonatal children, but also characterization of food-stuffs, food packages and pharmaceutical preparations. Non-biological applications include the study of construction materials such as wood, polystyrene foams and ceramics. For nano-porous materials, information on the pore sizes can be obtained from observed line broadening. Apart from concentration measurements, the GASMAS technique also allows the study of gas transport and diffusion, and pressure and temperature information can also be obtained.
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| 9. |
- Xu, Can, et al.
(author)
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Upconverting nanoparticles for pre-clinical diffuse optical imaging, microscopy and sensing : Current trends and future challenges
- 2013
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In: Laser and Photonics Reviews. - : Wiley. - 1863-8880. ; 7:5, s. 663-697
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Research review (peer-reviewed)abstract
- Upconverting nanoparticles (UCNPs) are a class of recently developed luminescent biomarkers that - in several aspects - are superior to organic dyes and quantum dots. UCNPs can emit spectrally narrow anti-Stokes shifted light with quantum yields which greatly exceed those of two-photon dyes for fluence rates relevant for deep tissue imaging. Compared with conventionally used Stokes-shifting fluorophores, UCNP-based imaging systems can acquire completely autofluorescence-free data with superb contrast. For diffuse optical imaging, the multiphoton process involved in the upconversion process can be used to obtain images with unprecedented resolution. These unique properties make UCNPs extremely attractive in the field of biophotonics. UCNPs have already been applied in microscopy, small-animal imaging, multi-modal imaging, highly sensitive bioassays, temperature sensing and photodynamic therapy. In this review, the current state-of-the-art UCNPs and their applications for diffuse imaging, microscopy and sensing targeted towards solving essential biological issues are discussed.
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