Richard Zeleny

• Ph.D.
• Czech Technical University in Prague

In recent years, a lot of attention has been directed towards the fabricating of smart structures with embedded optical sensors providing in-situ, non-destructive and real time or on-demand information of the construction structural health.

In this paper, the fiber Bragg gratings are investigated in the context of sensing of deformation inside a sample of a glued laminated timber. For this purpose, a fiber with acrylate recoated Bragg grating is placed and glued between the timber laminates. Since there are still some open questions leading now, one of the goals is to specify, if the se...

The paper deals with the experimental analysis focused on the determination of strain in wooden building structures using optical fibers with FBG sensors. Firstly, optical fibers were used to measure displacements of layers and surface strain of the lower surface of the ceiling panels made from mechanically jointed cross laminated timber (CLT). The...

In this paper, an effectively single mode reasonably bendable leakage channel fibre is designed having the highly nonlinear As2S3 chalcogenide glass as the fibre background. The fibre is designed to have effective mode area as large as possible as well as to have low confinement loss in the bent fibre. The fibre modal properties are calculated thro...

Optical fibres are widely used in various applications as a medium for optical signals or optical transfer. This transport can be realized on long distance, compared to free space optics, which significantly extends reach of applications. Free space optics and fibre optics are combined in practice to yield the maximum performance of individual comp...

The generally accepted view is that photonic crystal fibers (PCFs) with a small effective mode area allow the control of chromatic dispersion in the near-infrared region. For this purpose, a silica index guiding PCF with hexagonal cladding is investigated to find its dispersion limitation. In addition, chromatic dispersion is entirely controlled by...

Knowing a thermal expansion coefficient and measured exact thermal expansion, it is possible to design a very sensitive sensor measuring temperature differential. A Michelson interferometer is used to determine temperature changes. It measures linear expansion on a metal object, e.g. a copper rod, as a change in length in response to a change in te...

Nonlinear photonic crystal fibers with small effective mode area allow to control chromatic dispersion in the near-infrared region. In this paper the chromatic dispersion is controlled entirely by structural parameters and the influence of each structural parameter is examined and described in detail. Understanding of the influence not only permits...

In this paper we investigate limits of intensity and phase modulation formats used in optical communications. Non-Return to Zero, Return to Zero, Chirped Return to Zero, Carrier-Suppressed Return to Zero, Binary Phase Shift Keying, and Quadrature Phase Shift Keying including the most actual solutions, such as Polarization Division Multiplexing Quad...

A novel design of a photonic crystal fiber is presented. A nearly zero dispersion regime of operation has been achieved by using a three-fold symmetry core, which is improved by the avoidance of high-index doping in a central region. The core consists of pure silica surrounded by three fluorine-doped regions and three airholes. It can be confirmed...

The goal of this paper is to investigate selected fluoride optical materials and to present a photonic crystal fiber designed for specific applications in dispersion compensation by using those materials. The idea how to restrict chromatic dispersion is to increase the index contrast by using calcium fluoride or barium fluoride in the first ring of...

A novel photonic crystal fiber for compression of optical pulses is designed and studied in this paper. The fiber comprises a silica core surrounded by nine rings of air-holes, where air-hole diameter of the innermost ring is gradually reduced along the entire fiber length. In order to obtain the required wavelength dependence of the effective refr...

A new type of dispersion flattened photonic fiber is presented. The fiber has an improved threefold symmetry core that consists of a silica core surrounded by three low-index regions and three air-holes. It can be observed from numerical simulation employing the full-vectorial finite difference frequency domain method that nearly-zero ultra-flatten...

Presented work is a study of dispersion properties of photonic crystal fibers. The main objective is to design photonic crystal fibers suitable for potential compensation of group velocity dispersion of optical signals. New fiber structures are proposed, for example, a flattened-dispersion compensating photonic crystal fiber for broadband utilizati...