A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

The diffraction tomography theorem is adapted to one-dimensional length measurement. The resulting spectral interferometry technique is described and the first length measurements using this technique on a model eye and on a human eye in vivo are presented.

Measurement of intraocular distances by backscattering spectral interferometry

Vegetation Indices (VIs) obtained from remote sensing based canopies are quite simple and effective algorithms for quantitative and qualitative evaluations of vegetation cover, vigor, and growth dynamics, among other applications These indices have been widely implemented within RS applications using different airborne and satellite platforms with recent advances using Unmanned Aerial Vehicles (UAV) Up to date, there is no unified mathematical expression that defines all VIs due to the complexity of different light spectra combinations, instrumentation, platforms, and resolutions used Therefore, customized algorithms have been developed and tested against a variety of applications according to specific mathematical expressions that combine visible light radiation, mainly green spectra region, from vegetation, and nonvisible spectra to obtain proxy quantifications of the vegetation surface In the real-world applications, optimization VIs are usually tailored to the specific application requirements coupled with appropriate validation tools and methodologies in the ground The present study introduces the spectral characteristics of vegetation and summarizes the development of VIs and the advantages and disadvantages from different indices developed This paper reviews more than 100 VIs, discussing their specific applicability and representativeness according to the vegetation of interest, environment, and implementation precision Predictably, research, and development of VIs, which are based on hyperspectral and UAV platforms, would have a wide applicability in different areas

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Significant remote sensing vegetation indices: A review of developments and applications

We report simultaneous transmission of six spatial and polarization modes, each carrying 40 Gb/s quadrature-phase-shift-keyed channels over 96 km of a low-differential group delay few-mode fiber. The channels are successfully recovered by offline DSP based on coherent detection and multiple-input multiple-output processing. A penalty of ;28 dB.

Mode-Division Multiplexing Over 96 km of Few-Mode Fiber Using Coherent 6 $\,\times\,$ 6 MIMO Processing

A new concept for a fiber-based wavelength-tunable condensing lens is theoretically and experimentally investigated in terms of its ability to shift the longitudinal focus position as a function of wavelength. By exploiting multimode interference effects with reimaging theory, a compact and robust device, completely contained within a standard FC connector, can be constructed by simply splicing a single-mode fiber (SMF) to a finite length section of multimode fiber (MMF). This paper summarizes the theoretical and experimental results of such a device, with additional results for wavelength sensitivity.

Wavelength tunable fiber lens based on multimode interference

A novel design for an all-fiber bandpass filter based on a multimode interference reimaging phenomenon is presented. The filter has achieved low insertion loss with adequate bandwidth and isolation for coarse wavelength-division multiplexing. The filter can easily be made with any central wavelength that is compatible with the single-mode fiber used for its construction. The measured filter performance matches the theoretical predictions well. The filter can have broad applications in fiber-optic telecommunications, spectroscopy, and sensing.

All-fiber multimode interference bandpass filter

A new concept for a multimode interference-based fiber-optic displacement sensor is investigated both theoretically and experimentally. By applying multimode interference and reimaging theory to optical fibers, a displacement sensor consisting of only a section of multimode fiber fusion spliced to a single-mode fiber can be readily fabricated. Observation and analysis of the power reflected off of a surface and back through the device over a finite wavelength range provides enough information to use the device as a calibrated displacement sensor over a large displacement range.

Multimode interference-based fiber-optic displacement sensor

The present invention relates to a system and method to determine chromatic dispersion in short lengths of waveguides using a two wave interference pattern and a common path interferometer. Specifically the invention comprises a radiation source operable to emit radiation connected to a means for separating incident and reflected waves; the means for separating incident and reflected waves possessing an output arm adjacent to a first end of the waveguide; and the means for separating incident and reflected waves further connected to an optical detector operable to record an interference pattern generated by a reflected test emission from the radiation source. The interference pattern consists of two waves: one reflected from a first facet of a waveguide and the second reflected from a second facet of the same waveguide.

System and method to determine chromatic dispersion in short lengths of waveguides using a common path interferometer

In this article, we propose a two-dimensional indoor localization system using fingerprinting of received optical signals emitted from light emitting diodes (LEDs). The transmitters and receiver are designed and constructed to use visible light as the signal for localization. At the transmitter side, the input voltage/current is modulated with continuous waves before being sent to the LEDs, where each transmitter is assigned with a different frequency. At the receiver side, the power spectral density of the received signal is calculated and the location is estimated as one of the fingerprint locations using a novel but yet simple algorithm. Both the simulation and experiment have been conducted to evaluate the accuracy of the system in a controlled environment. We demonstrate that the system has the potential to estimate locations in the level of centimeters. V C 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1218-1227, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26763

Waleed S. Mohammed

Papers

Wavelength tunable fiber lens based on multimode interference

All-fiber multimode interference bandpass filter

Multimode interference-based fiber-optic displacement sensor

System and method to determine chromatic dispersion in short lengths of waveguides using a common path interferometer

A fingerprinting-based indoor localization system using intensity modulation of light emitting diodes