Fresnel waveguides

Combination of Surface Plasmon Resonance (SPR) and Optical Waveguide Spectroscopy (OWS) was used for the simultaneous determination of refractive index and film thickness of the hydrogel layers in the Kretschmann configuration [24], The resulting angle scans from the SPR instrument were fit to Fresnel calculations and different layers were represented using a simple box model. A detailed description of this process has been published previously [18]. 

We now consider a light wave with 1 = polarized in the x-direction, traveling in the waveguide between the two interfaces, waveguide-cover and waveguide-substrate. The wave will be reflected at the interfaces with angles cpc and (ps for cover and substrate, respectively. Since we assume the electric held is parallel to the interfaces, a phase shift of Tj will occur at each interface according to Fresnel s formulas, while the amplitude and polarization remain the same. Additionally, we assume for simplicity that (pc = [Pg.26]

Fig. 15 Waveguide spectra (p-poL) of a 740 nm thick (dry thickness) MePVP brush covalently attached to the surface of a LaSFN9/Au/Si02 substrate. The spectra were measured in different (constant) rel. humidities a = 0%, b = 35%, c = 70%, d = 87% and e = 100% rel. humidity at 25°C. The solid lines are the calculated reflection curves obtained from Fresnel modeling...

We have used a femtosecond-written Nd YAG ceramic optical waveguide as an active media to achieve continuous wave 1.06 pm laser operation. We have obtained output laser power of 40 mW and with a laser slope efficiency in excess of 40%. Single mode and stable laser oscillation have been achieved by using the natural Fresnel reflection for optical feedback without the requirement of any kind of mirror or reflective component. 

The loss of the NLO polymer and UV-cured resin of this QPM waveguide were 0.67 dB/ cm and 0.53 dB/cm, respectively. The Fresnel reflection loss of the grafted interface was... 

Another mechanical solution to the problem of Fresnel specular reflectance is cutting off the specular component at the exit aperture of the accessory, as shown in Fig. 4.25 [154]. The waveguide that filters the KM component from the scattering radiation in the cup-on-the-saucer DRIFTS accessory (Fig. 4.19) may also be regarded as a mechanical device. 

Techniques for the formation of intense X-ray microbeams are readily available using various types of X-ray optics. Bent mirrors, crystals and multilayers, tapered glass monocapillaries, complex polycapillary lens systems, Bragg-Fresnel lenses, one- or two-dimensional waveguides, and refractive lenses have been developed and tested for use in micron (pm) size to... 

The refractive index depends on the propagation of light as well as the reflected and transmitted fractions of incident waves on an interface. The Fresnel coefficients for reflection and transmission are given by the refractive indices of the two adjacent materials. For many applications of porous silicon in optics or optoelectronics, it is necessary to know the exact refractive index (see, e.g., chapters Porous Silicon Photonic Crystals, Porous Silicon Optical Waveguides, Porous... 

X- radiation is very energetic and has been very difficult to manipulate. It can be focused either coherently by Fresnel zone plates and Bragg Fresnel lenses, or incoherently by bent crystal optics and coated fiber optics (generally speaking by highly reflective materials, e.g. super mirrors etc.). However, for many applications, such as X-ray microscopy and spectroscopy, the spot size at the exit of the aperture is too large and the beam stmcture is difficult to control. Moreover, in order to use X-ray in non-invasive medical treatments there is a need for an X-ray waveguide. 

Figure 9 (a) Film thickness of PMMA monolayers as a function of monomer concentration during the polymerization reaction (temperature 60°C, t = 18 h) all samples have been extracted with toluene after stopping of the polymerization reaction for 20 to 48 hours (b) waveguide spectrum of a 1690 nm thick PMMA layer solid line is a calculation according to Fresnel equations. 

Figure 13 Waveguide-spectra (p-polarization) of (a) 230 nm, (b) 520 nm, and (c) 1030 nm thick PVP layers on glass/silver (50 nm)/SiOx (30 nm) substrates. The layers were prepared on the substrates by radical polymerization of 4-vmylpyridine in benzene (50 mol%) at 60°C for 4.5, 6, and 24 hours, respectively. After polymerization the substrates were extracted for 15 hours in methanol. The solid lines are the calculations according to the Fresnel equations.

The transmission coefficient T is found by using the local plane-wave description of a ray. We regard the local plane wave as part of an infinite plane-wave incident on a planar interface between unbounded media, whose refractive indices coincide with the core and cladding indices and of the waveguide, as shown in Fig. l-3(b). For the step interface, Tis identical to the Fresnel transmission coefficient for plane-wave reflection at a planar dielectric interface [6]. In the weak-guidance approximation, when s n, the transmission coefficient is independent of polarization, and is derived in Section 35-6. From Eq. (35-20) we have [7]... 

Snyder, A. W. and Mitchell, D, J, (1974) Generalized Fresnel s laws for determining radiation loss from optical waveguides and curved dielectric structures. Optik, 40, 438-59. 

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