Tunable optics

Hollow gold spheres or core-shell particles consisting of a gold shell on a core of some other material have recently attracted attention. This is because they have interesting and tunable optical extinction properties [56]. These can be readily calculated using Mie theory [57], and there had been some scattered early interest in these shapes as a result [58, 59], but the versatility and properties of these particles only became widely... 

High-Temperature Crystallization The size-tunable optical and electronic properties of semiconductor nanocrystals are attractive for a variety of optoelectronic applications. In solution-phase crystallization, precursors undergo chemical reaction to form nuclei, and particle growth is arrested with capping ligands that... 

The fundamental physical properties of nanowire materials can be improved even more to surpass their bulk counterpart using precisely engineered NW heterostructures. It has been recently demonstrated that Si/Ge/Si core/shell nanowires exhibit electron mobility surpassing that of state-of-the-art technology.46 Group III-V nitride core/shell NWs of multiple layers of epitaxial structures with atomically sharp interfaces have also been demonstrated with well-controlled and tunable optical and electronic properties.47,48 Together, the studies demonstrate that semiconductor nanowires represent one of the best-defined nanoscale building block classes, with well-controlled chemical composition, physical size, and superior electronic/optical properties, and therefore, that they are ideally suited for assembly of more complex functional systems. 

Tumorigenic responses, 25 222-223 Tumor necrosis factor (TNF) role in hemostatic system, 4 89 Tumors, hydrazine-related, 23 590—591 Tunable diode lasers (TDLs), 23 143 Tunable diode laser systems, 23 138 Tunable optical properties, windows with, 23 25... 

Windows, with tunable optical properties, 23 25. See also Smart windows WindStor system, 25 526 Wind-turbine-generator system electricity produced by, 26 94 Wine Aroma Wheel, 26 325 Wine, 26 295-332, 3 561-562... 

Conventional SERS substrates typically have disordered nanoscale features, such as that found in electrochemically roughened Au or Ag surfaces.170 SERS substrates can also be rationally designed by lithography, by self-assembly, or a combination of the two. Both supramolecular and nanoscale self-assembly methods can be used to fabricate two-dimensional Au nanoparticle arrays with tunable optical properties.33 171172 For example, macrocyclic surfactants based on resorcinarenes (a subclass... 

Recent advances in solid-state laser systems offer several potential improvements. In particular, tunable optical parametric amplifiers provide tunable pulses with excellent synchronization and beam quality. However, most reported systems produce pulses of <100 fs. Pulses this short are not needed to measure vibrational dephasing in most systems, and they unnecessarily exacerbate the problems of self-focusing and excitation of overtone transitions. A solid-state system optimized for longer pulses has... 

Essentially, a small part of the laser pulse train that is ultimately used to trigger the photocathode is split off to create a synchronized laser probe pulse train. The probe line is equipped with different nonlinear optical devices that permit the tunability of the probe beam from the near UV to the NIR. Available probe sources include the laser fundamental (790 nm) and second harmonic (395 nm), a white-light continuum (470-750 nm) generated in a sapphire plate, and a continuously tunable Optical Parametric Amplifier (470-750 nm, 1000-1600 nm, and 240-375 nm by SHG), able to deliver light pulses shorter than 30 fs after compression. 

The ability to synthesize carbon nanostmctures, such as fullerenes, carbon nanotubes, nanodiamond, and mesoporous carbon functionalize their surface or assemble them into three-dimensional networks has opened new avenues for material design. Carbon nanostructures possess tunable optical, electrical, or mechanical properties, making them ideal candidates for numerous applications ranging from composite structures and chemical sensors to electronic devices and medical implants. 

Yoshino, K., Satoh, S., Shimoda, Y. et al.. Tunable optical properties of conducting polymers infiltrated in synthetic opal as photonic crystal, Synthet. Met., 121, 1459, 2001. 

Dinakar Ramadurai, Babak Kohanpour, Dimitri Alexson, Peng Shi, Akil Sethuraman, Yang Li, Vikas Saini, Mitra Dutta, and Michael A. Stroscio, Tunable optical properties of colloidal quantum dots in electrolytic environments, lEE Proceedings in Nanobiotechnology, 151, 189-192 (2004). 

ShimM., Wang C. and Guyot-Sionnest P. J. (2001), Charge-tunable optical properties in colloidal semiconductor nanocrystals , J. Phys. Chem. 105, 2369-2373. 

Park, S.H. and Xia, Y., Crystallization of meso-scale particles over large areas and its appheation in fabricating tunable optical filters, Langmuir, 15, 266, 1999. 

A. S. Zelenina, R. Qnidant, G. Badenes, and M. Nieto-Vesperinas, Tunable optical sorting and manipulation of nanoparticles via plasmon excitation. Optics Letters 31 p. 2054-2056 (2006). 

TMS is grateful for the efforts of his many excellent coworkers. This research was sponsored by the Defense Advanced Project Agency, the Office of Naval Research, and the Army Research Office through the Tunable Optical Polymers MURI. 

TERS and theory TERS also provides excellent stimulation and a playground for theoretical studies on enhanced optical processes. The tip-substrate configuration can be considered as a unique photonic system with tunable optical resonances that provides huge near-field enhancements for species located in the tip-substrate cavity. A suitable theoretical description of such a photonic system is, even today, a great challenge, although the general features of such a system are well understood. 

Wang, Z., Folkenroth, J., Zhou, W., Zhang, Y., and Shi, X. (2012). Cellulose ether polymers as optical compensation fUms for LCDs-high birefringence and tunable optics, IDW/AD 12, Kyoto, Japan, pp. 499-502. 

The broad spectral coverage for luminescence from the ultraviolet (UV) to the NIR offered via the tunability of composition, size and shape in semiconductor nanocrystals, presents an obvious advantage for the use of such materials as tunable optical gain media, and in laser applications. Furthermore, low lasing thresholds are predicted for QDs and quantum wires, compared with two-dimensionally confined quantum wells, form the basis of the present semiconductor diode laser devices which are ubiquitous in information and telecommunication technologies [86, 87]. 

A variety of devices have been designed by using transparent electro-optical ceramic materials, including variable optical attenuators (VOA), polarization controllers (PC), sinusoidal filters, dynamic gain flattening filters, tunable optical filters, and (2-switches, which have been described in detail in Ref. [129]. A brief description is given for some devices as follows. 

P.-T. Wu, T. Bull, E S. Kim, C. K. Luscombe, S. A. Jenekhe, Organometallic Donor-Acceptor Conjugated Polymer Semiconductors Tunable Optical, Electrochemical, Charge Transport, and Photovoltaic Properties. Macromolecules 2009,42, 671-681. 

Fig. 6.44 Tunable optical parametric amplifier with a white fight source and a blue pump...

In addition, short-pulse tunable optical parametric oscillators have been realized, where the pump wavelength and the signal or idler waves can be used for... 

Acharya BR, Rmpenkin T, Ramachandran S, Wang Z, Huang CC, Rogers JA (2003) Tunable optical fiber devices based on broadband long-period gratings and pumped microfluidics. Appl Phys Lett 83 4912-4914... 

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