A portable confocal hyperspectral microscope without any scan or tube lens and its application in fluorescence and Raman spectral imaging

Abstract

Abstract. In this paper we prove the existence of Hall's ray for the quadratic Lagrange spectrums of all real quadratic numbers. For a large class of real quadratic numbers, we compute the Hurwitz constants of their quadratic Lagrange spectrums.

Light-Sheet Microscopy for Surface Topography Measurements and Quantitative Analysis

“…By subtracting the horizontal value of the pixel location of each of the 301 recorded contour lines with that of the first contour line, we obtain 300 ∆n pixel -values. These are defined as the equivalent to the physical offset length ∆x in the surface plane of the CMOS camera such that ∆x = ∆n pixel × size pixel (7) where size pixel is the size of the pixels in µm. We can then derive a relationship between ∆n pixel and ∆z that is equivalent to Equation ( 6) by fitting a 5th-order polynomial, the result of which is plotted in Figure 4.…”

“…To avoid this drawback, several non-contact optical technologies that construct 3D spatial models through microscopic imaging have been proposed. For example, laser-scanning confocal microscopy [6,7] illuminates a point which is confocal, with the pinhole in front of the photodetector; multiphoton microscopy [8] excites the point in focus; structured light projects the surface for shape measurement [9]; and stereo vision [10,11] captures multi-angle images for inspection without active illumination. Point-scanning microscopy techniques are, however, limited by 2D movements, causing low imaging efficiency.…”

An Approach to Measuring the Point Spread Function of the Confocal Raman Microscope

“…15 An alternative is to use the testing targets such as the USAF1951 resolution test chart, but its precision is limited by the target size. 16 The PSF method, which is widely used to evaluate the performance of optical systems, such as the confocal microscope 17 and the optical coherence tomographic system, 18,19 can reflect all possible influential factors in the imaging process of CRM. Since the PSF of a typical CRM is co-determined by the microscope, the laser beam shaping system, and the spectrum collecting system, it is difficult to obtain an accurate theoretical model of CRM.…”

Recent advances in nano-photonic techniques for pharmaceutical drug monitoring with emphasis on Raman spectroscopy

“…As an optical, chemically selective method, Raman spectroscopy allows the identification and quantification of numerous molecules simultaneously in different media in a non-destructive way [18][19][20][21][22][23][24][25][26][27]. Thanks to recent advances in instrumentation, portable devices [28][29][30][31][32] are available and applied on-site, e.g. for drug sensing [33][34][35][36][37][38][39] in forensics [28,29,31,40] and in the pharmaceutical industry [32].…”