#2A. Jaimes-Nájera(National Institute of Astrophysics, Optics and Electronics)H-Index: 2
Last. S. Chávez-Cerda(National Institute of Astrophysics, Optics and Electronics)H-Index: 1
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To the best of our knowledge, at the present time there is no answer to the fundamental question stated in the title that provides a complete and satisfactory physical description of the structured nature of Hermite-Gauss beams. The purpose of this manuscript is to provide proper answers supported by a rigorous mathematical-physics framework that is physically consistent with the observed propagation of these beams under different circumstances. In the process we identify that the paraxial appro...
The angular momentum (AM) of light has important implications for many fields of optics research, such as optics communication, quantum information and laser-scan microscopy. Thus, in this paper, we intend to investigate the average AM of the vortex ultrashort pulsed beam (VUPB), which is generated and widely applied in the field of high-intensity and ultrafast regimes. According to the vector potential, we firstly derive the electromagnetic field of the VUPB, then analyze the spatial intensity,...
The Rindler space-time describing a series of accelerating observers is Ricci flat, but it still has novel optical effects. In the case of Wenzel, Kramers, and Brillouin (WKB) approximation, we derive the light paths in the Rindler frame based on the covariant wave equation and geodesic equations. Then, we use ABCD matrix optics method to explore the propagation characteristics of Rindler frame, thus link three different optical transformation scenes (geometry, gravity, and vacuum refractive ind...
Last. Hongyan Fu(THU: Tsinghua University)H-Index: 11
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In this work, we propose an ultra-broadband and ultra-compact polarization beam splitter (PBS) on a standard silicon-on-isolator platform. Assisted by a tapered subwavelength-grating waveguide and a slot waveguide, the working bandwidth of the directional-coupler-based PBS covers the entire O-, E-, S-, C-, L- and U-bands and the coupling length is only 4.6 µm. The insertion losses (ILs) of the device are simulated to be less than 0.8 dB and the extinction ratios (ERs) are larger than 10.9 dB at ...
Large depth-of-field (DOF) imaging with a high resolution is useful for applications ranging from robot vision to bio-imaging. However, it is challenging to construct an optical system with both a high resolution and large DOF. The common solution is to design relatively complex optical systems, but the setup of such systems is often bulky and expensive. In this paper, we propose a novel, compact, and low-cost method for large-DOF imaging. The core concept is to (1) design an aspherical lens wit...
#1Jelmer Cnossen(TU Delft: Delft University of Technology)H-Index: 4
#2Tao Ju Cui(TU Delft: Delft University of Technology)H-Index: 5
Last. Carlas Smith(TU Delft: Delft University of Technology)H-Index: 11
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Localization microscopy offers resolutions down to a single nanometer but currently requires additional dedicated hardware or fiducial markers to reduce resolution loss from the drift of the sample. Drift estimation without fiducial markers is typically implemented using redundant cross correlation (RCC). We show that RCC has sub-optimal precision and bias, which leaves room for improvement. Here, we minimize a bound on the entropy of the obtained localizations to efficiently compute a precise d...
Vibration measurement, particularly mode shape measurement, is an important aspect of structural dynamic analysis since it can validate finite element or analytical vibration models. Scanning laser Doppler vibrometry (LDV) and high-speed digital image correlation have become dominant methods for experimental mode shape measurement. However, these methods have high equipment costs and several disadvantages regarding spatial or temporal performance. This paper proposes a laser Doppler vibrometer i...
The correction of uneven illumination in microscopic image is a basic task in medical imaging. Most of the existing methods are designed for monochrome images. An effective fully convolutional network (FCN) is proposed to directly process color microscopic image in this paper. The proposed method estimates the distribution of illumination information in input image, and then carry out the correction of the corresponding uneven illumination through a feature encoder module, a feature decoder modu...
Single-molecule spectroscopy has been extensively used to investigate heterogeneity in static and dynamic behaviors on millisecond and second timescales. More recently, single-molecule pump-probe spectroscopy emerged as a method to access heterogeneity on the femtosecond and picosecond timescales. Here, we develop a single-molecule pump-probe apparatus that is easily tunable across the visible region and demonstrate its utility on the widely-used fluorescent dye, Atto647N. A spectrally-independe...
We demonstrate a dual-material integrated photonic thermometer, fabricated by high accuracy micro-transfer printing. A freestanding diamond micro-disk resonator is printed in close proximity to a gallium nitride on a sapphire racetrack resonator, and respective loaded Q factors of 9.1 × 104 and 2.9 × 104 are measured. We show that by using two independent wide-bandgap materials, tracking the thermally induced shifts in multiple resonances, and using optimized curve fitting tools the measurement ...