Fiber-optic chemical sensing has been demonstrated with a side-polished single-mode optical fiber, evanescently coupled to chemically sensitive Langmuir-Blodgett (LB) overlay waveguides. The sensors exhibit a channel-dropping response centered on a wavelength that is dependent on the thickness and the refractive index of the overlay waveguide. It has been shown that pH-sensitive organic dyes pr...

Structural, optical and electronic properties and elastic constants of Be1–xZnxS alloys have been studied by employing the commercial code Castep based on density functional theory. The generalized gradient approximation and local density approximation were utilized as exchange correlation. Using elastic constants for compounds, bulk modulus, band gap, Fermi energy and Kramers–Kronig relations,...

A quantization scheme for the phenomenological Maxwell theory of the full electromagnetic field in an inhomogeneous three-dimensional, dispersive and absorbing dielectric medium is developed. The classical Maxwell equations with spatially varying and Kramers–Kronig consistent permittivity are regarded as operator-valued field equations, introducing additional currentand charge-density operator ...

We discuss the linear dispersive properties of finite one-dimensional photonic band-gap structures. We introduce the concept of a complex effective index for structures of finite length, derived from a generalized dispersion equation that identically satisfies the Kramers-Kronig relations. We then address the conditions necessary for optimal, phase-matched, resonant second harmonic generation. ...

Multiple-wave Diffraction Anomalous Fine Structure (MDAFS), a new method combining the X-ray multiple-wave diffraction with diffraction anomalous fine structure (DAFS) technique, provides the long-range order structure information by measuring the multiple-wave diffraction profiles in the vicinity of an absorption edge. The real part of dispersion correction and fine structure function can be o...

We briefly review the electrical-optical response of materials to radiative forcing within the formalism of the Kramers-Kronig relations. A commensurate set of criteria is described that must be met by any frequency-domain model representing the time-domain response of a real (i.e., physically possible) material. The criteria are applied to the Brendel-Bormann (BB) oscillator, a model that was ...