INDEX microspheres

Fig. 7 Solid-immersion micropshere superlens, (a) planar design with high-index microsphere embedded in transparent layer, (b) hemisphere-top design which reduces total internal refection (TIR) effect of planar surface, (c) lab prototype produced at Bangor University, and (d) imaging example showing 40 nm lines can be clearly imaged.

Teraoka, I. Arnold, S., Enhancing the sensitivity of a whispering gallery mode microsphere sensor by a high refractive index surface layer, J. Opt. Soc. Am. B 2006, 23, 1434 1441... 

Here n5 and nm are the refractive indices of the microsphere and ambient medium, respectively, and R is the microsphere radius. To determine An and t from this equation, it is sufficient to measure AA for two wavelength, ly1 and A. In Ref. 36, this was done for A[ = 760 nm and A[ = 1,310nm. As the result the authors optically characterized a hydrogel nanolayer with 110-nm thickness and an extremely small excess refractive index of 0.0012, which was formed in situ in an aqueous environment. 

Fig. 13.26 (a) Set of parallel MNFs and parallel microcylinders coupled to each other, (b) Two microspheres coupled to an MNF (from Ref. 38). (c) Two microcapillaries coupled to an MNF imbedded in a low index polymer. Reprinted from Ref. 69 with permission. 2008 Optical... 

The fiber-taper coupling scheme was applied to liquid-immersed water-droplet microsphere resonators by Hossein-Zadeh and Vahala35. The water droplets of diameter 0.5 1 mm were generated by a syringe and immersed in a low refractive immiscible cladding liquid - an index matching oil with a refractive index of 1.3, and trapped on a silica sphere which was fixed to the bottom of a liquid container... 

Chylek et al. (1983) showed that, by comparing experimental resonance spectra with spectra computed using Mie theory, the size and refractive index of a microsphere can be determined to about one part in 10. Numerous investigators have used resonance spectra to determine the optical properties of microspheres since Ashkin and Dziedzic observed resonances. A recent example is the droplet evaporation study of Tang and Munkelwitz (1991), who measured the vapor pressures of the low-volatility species dioctyl phthalate (DOP), glycerol, oleic acid, and methanesulfonic acid (MSA). This... 

Phase functions can also be used to measure the size and refractive index of a microsphere, and they have been used by colloid scientists for many years to determine particle size. Ray et al. (1991a) showed that careful measurements of the phase function for an electrodynamically levitated microdroplet yield a fine structure that is nearly as sensitive to the optical parameters as are resonances. This is demonstrated in Fig. 21, which presents experimental and theoretical phase functions obtained by Ray and his coworkers for a droplet of dioctylphthalate. The experimental phase function is compared with two... 

Fig. 2. A portion of the experimentally observed fluorescence spectrum from a 2 pm radius PMMA microparticle (top) and the calculation of scattering efficiency (bottom) for a microsphere of radius 1.77 pm (ref. index - 1.49). First order MDR are dominant in the experiment.

Table IV gives the Attrition Indexes for the commercial and experimental samples. These values are reported for microspheres that were spray dried before the viscosity of the slurry exceeded 100 cP. The data show, again, that sol age and particle size of the CP alumina affect attrition. Sol age also seems to reduce the influence of the CP-2 as a binder. The Reference (4) has an AI of about 3 which is comparable to the index for CP-2(4). The important point here is that the alumina particles can be incorporated into a standard FCC formula to change catalytic activity without a detrimental effect on attrition resistance.

Studies have shown that drug delivery systems such as microspheres, nanoparticles, and liposomes are able to improve the therapeutic index of cancer... 

Fig. 7 compares the experimentally measured (A and C) absorption Cahs,x and (B and D) scattering Csca,x cross-sections between 400 and 700 nm of monodisperse latex spheres 2.02 and 4.5 pm diameter with Lorenz—Mie theory predictions using the complex index of refraction of latex reported by Ma et al. (2003). Flere also, the good agreement between theoretical and experimental results successfully validated the experimental setup and the data analysis. Similar vaHdation has been performed with the same polydisperse polystyrene latex microspheres and randomly oriented and infinitely long glass fibers considered for validating the scattering phase function measurements, as illustrated in Fig. 6 (Berberoglu and Pilon, 2007).

Ma X, LuJQ, Brock RS, Jacobs KM, Yang P, Hu HH Determination of complex refractive index of polystyrene microspheres from 370 to 1610 nm, Phys Med Biol 48 4165—4172, 2003. 

To study the flow within the capillaries, the aqueous phase was seeded with fluorescent microsphere suspensions at 1 % concentration by weight (Thermo Scientific). The fluorescent micro-spheres are made of polystyrene and were dyed with red or blue fluorescent dyes. The refractive index and the density are 1.59 and 1.06 g cm, respectively. The spectral properties of the fluorescent microspheres are shown in Table 3.3. The size of the particles varied between 1 and 3.2 pm depending on the channel size. 

It is a non-resonant phenomenon that can appear for a certain range of the diameter d of the dielectric microsphere or microcylinder from 22 to more than 402 if the refractive index contrast relative to the background medium is less than about 2 1. 

Fig. 8 Decoupling of high spatial frequency evanescent waves by the particle-substrate system in microsphere nanoscope. Incident wavelength 600 nm, particle size 4.7 pm, refractive index 1,46,...

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