OBJECTIVE To evaluate the effects of the intrastromal corneal ring, a device developed to reduce myopia, on corneal asphericity in a large set of eye bank eyes. METHODS Forty-one deturgesced eye bank eyes were implanted with intrastromal corneal rings of five different thicknesses, ranging from 0.25 mm to 0.45 mm. Corneal asphericity, before and after implantation, was examined using two diff...

Phase-measurement interferometry (PM!) techniques enable quantitative measurements to be performed in optical testing, holographic interferometry, and speckle metrology. This paper will present results of error analyses of the most common errors in phase-measurement techniques. These errors include miscalibrated and nonlinear phase shifters, detector nonlinearities, detection quantization, vibr...

We combine optical methods for sensing of oil films. These are: coherent fringe projection (CFP), digital holographic in-line interferometry (DHILI). The methods of CFP and DHILI are described as coherent superposition of partial interference patterns OCIS codes; 090.0050, 090.199,120.2880

Electronic heterodyne moire deflectometry and electronic heterodyne holographic interferometry are compared as methods for the accurate measurement of refractive index and density change distributions of phase object p . Experimental results are presented to show that the two methods have comparable accuracy for measuring the first derivative of the intE-ferometric fringe shift. The phase objec...

In phase-shifting interferometry experiments, the accuracy of the phase shift is a major issue. Many experimental and data analyses are done to cancel phase-shift errors inherent to the modulation techniques used. We propose to remove most of the phase-shift error by recourse to a frequency-shifting method. This approach can be applied to both holography and interferometry. We validate the idea...

A current problem encountered in holographic interferometry systems is the phase variations that arise from vibrations, from the use of optical fiber in one arm, by air convection or by unwanted movement between the object and the measurement device. The holographic device developed by CSL based on photorefractive BSO crystals has the advantage of high resolution fringes with the capability of ...

This paper proposes a new approach for the analysis of reconstructed interference fields in digital holographic interferometry. In the proposed approach the interference phase to be estimated is conceived as a piecewise polynomial signal; consequently, each segment of the reconstructed interference field is modeled as a polynomial phase signal (PPS) with constant or slowly varying amplitude. Un...

This study compared the transmission of tensions in fresh, fixed and macerated dog mandibles in order to clarify the diversity of behavior of bone tissues under dry and moist conditions. Double-exposure holographic interferometry was applied and holograms were obtained from 12 fresh hemi-mandibles under static load (control group), which were randomly assigned to 2 groups: 6 were fixed in 10% f...

In digital holography holograms are recorded by a CCD and image reconstruction is performed by a computer. It is free from tedious photographic processing and delivers three-dimensional distributions of both amplitude and phase quantitatively. Its main limitation that is caused by much lower resolution of CCDs than photographic materials has been substantially overcome by phase-shifting digital...