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Glutamate concentration was determined in serum from endogenous and neurotic depressive patients, in persons with schizophrenia or schizoaffective disorder, and in normal subjects. The mean serum glutamate level in the endogenous and neurotic depressive patients was found to be significantly higher than in any of the other groups. No other statistically significant differences were found. Statistical analysis revealed that the elevated serum glutamate concentration in the endogenous and neurotic depressive patients was probably caused by medication. These results are discussed in view of the effect of antidepressants upon the serum glutamate in the affective disorders.

The Space-Bandwidth Product (SBP) is a measure for the information capacity an optical system possesses. The two information processing steps in digital holography, recording and reconstruction, are analysed with respect to the SBP. The recording setup for a Fresnel hologram, Fourier hologram and Image-plane hologram, which represent the most commonly used setup configurations in digital holography, are investigated. For the recording process, the required SBP to ensure the recording of the entire object information is calculated. This is accomplished by analysing the recorded interference pattern in the hologram plane. The paraxial diffraction model is used in order to simulate the light propagation from the object to hologram-plane. The SBP in the reconstruction process is represented by the product of the reconstructed field of view and spatial frequency bandwidth. The outcome of this analysis results in a space-bandwidth product optimised digital holographic setup. c

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Digital holography is a modern imaging technique whereby a propagated object wave interferes with a known (spherical or plane) reference wave at a plane where a digital sensor is situated. The resulting intensity distribution is recorded by a CCD or CMOS sensor array to produce a digital hologram. This digital hologram can be processed in several ways to isolate the real image term. Using a propagation algorithm, the object wave can be numerically reconstructed from this real image term. Several factors limit the performance of such imaging systems, such as the finite extent of the sensor array and the finite size of the equally spaced sensor pixels, which average the light intensity incident upon them. Theoretical results indicate that in a Fresnel-based system the role of these finite-size pixels is to attenuate higher spatial frequencies by convolving the reconstructed signal with a rectangular function of equal size to the light-sensitive area of the pixel. However, when a spherical reference wave is used, as is the case with "lensless" Fourier-based systems, spatial frequencies will not be attenuated; rather it is the complex amplitude of the reconstructed signal that will be attenuated. In this manuscript we explore this question in more detail, providing new theoretical and experimental results. By assuming a fully developed speckle field for the object wave, we examine the first-order statistical distributions for the integrated intensity of the object wave, and the interference term, using numerical simulations. We show that the statistical distribution of the interference term can be changed, by varying the sphericity of the reference wave. Experimental results are provided where we compare the performance of a Fresnel and Fourier holographic system as a function of pixel size.

We describe an experimental implementation of ptychography to optical metrology, in particular topography measurement, in combination with the dual wavelength method. This is the first published account of the application of the dual wavelength method to ptychography or any other phase retrieval method in order to obtain surface height information over a wide range of scales, from small fractions of a wavelength up to many tens of wavelengths, in reflection mode. Moreover, the work presented here is the first report on the application of lensless reflection mode ptychography. Advantages of the ptychographic dual wavelength method are compared with other optical topography measurement techniques, especially with respect to the experimental procedures and constraints and the analysis of the data. We show that dual wavelength ptychography can remove material-specific phase changes which adversely affect topography measurements using white light profilometry.

A new denoising algorithm for hyperspectral complex domain data has been developed and studied. This algorithm is based on the complex domain block-matching 3D filter including the 3D Wiener arXiv:1907.03104v1 [eess.IV] 6 Jul 2019 A PREPRINT -JULY 9, 2019 filtering stage. The developed algorithm is applied and tuned to work in the singular value decomposition (SVD) eigenspace of reduced dimension. The accuracy and quantitative advantage of the new algorithm are demonstrated in simulation tests and in processing of the experimental data. It is shown that the algorithm is effective and provides reliable results even for highly noisy data.