Explanipedia

Evaluating the Impact of Waste Eggshell-Derived Calcium-Enriched Nano-Fertilizer on Carrot plant ( <i>Daucus carota</i> ) Development Open

Ashutosh Kumar, Abhay Kumar Aman, Rakesh Kumar Singh, Farhan Khan · 2025

This study investigates the effects of calcium-enriched nano-fertilizer manufactured from discarded eggshells on the growth and development of carrot plants ( Daucus carota ) in order to evaluate a sustainable alternative to conventional f…

Statistics of Non-Rayleigh Speckles Generated from Nonlinear Media Open

Deependra Singh Gaur, Rakesh Kumar Singh, Akhilesh Mishra · 2025

We analytically derive an expression for a speckle field's intensity probability density function (PDF) in a nonlinear medium. The analytically driven results are in good agreement with the numerical outcomes. In a focusing nonlinear mediu…

Coherence vortices by binary pinholes Open

Akanksha Gautam, Amit K. Agarwal, Rakesh Kumar Singh · 2024

Singularity in a two-point complex coherence function, known as coherence vortices, represents zero visibility with a helical phase structure. In this paper, we introduce a novel technique to generate the coherence vortices of different to…

Massive mandibular ameloblastoma masquerading malignancy: A unique case Open

Rakesh Kumar Singh, Shruti Jha, Mani Mala, Kumar Amod, Sanjeet Goit · 2024

Ameloblastomas are odontogenic tumours that arise from the maxilla and mandible. They are mostly benign but can seldom turn malignant. Their low incidence (<1-3%) and ambiguous presentation can often pose a diagnostic dilemma for the c…

Dual-shot approach for polarization retrieval through a scattering medium Open

Abhijit Roy, Reajmina Parvin, Ankita Karmakar, Abhishek Mandal, Rakesh Kumar Singh , et al. · 2024

A dual-shot technique based on the field basis addition of two statistically independent speckle patterns is developed to recover an input polarization through a scattering layer. It is proposed theoretically, and demonstrated both numeric…

Effect of Polarization on Cross-Spectral Density Matrix Open

Akanksha Gautam, Dinesh N. Naik, C. S. Narayanamurthy, Rakesh Kumar Singh · 2024

Coherence-polarization properties of different beams are experimentally measured in the far-field from the source and results are presented for incoherent sources with three different polarization features, such as unpolarized, diagonally …

Influence of Primary Coma on the Tightly Focusing Characteristics of Circular Basis Hybrid Order Poincaré Sphere Beams Open

S.K. Pal, Rakesh Kumar Singh, P. Senthilkumaran · 2024

Analogous to the Poincaré sphere, a hybrid order Poincaré sphere is used to represent the ellipse field singularities (C-points). We study the tight focusing properties of generic bright and dark hybrid order Poincaré sphere beams in the p…

Influence of Primary Coma on the Tightly Focusing Characteristics of Circular Basis Hybrid Order Poincaré Sphere Beams Open

S.K. Pal, Rakesh Kumar Singh, P. Senthilkumaran · 2023

We study the tight focusing properties of generic bright and dark HyOPS beams in the presence of primary coma. The role of the polarization singularity index and handedness of the polarization of the HyOPS beams on the focused structure ha…

Bardet–Biedl Syndrome with Choledochal Cyst Open

Saket Kumar, A. G. Harisankar, Nidhi Singh, Rakesh Kumar Singh, Mayank Nilay · 2023

Bardet–Biedl syndrome is an autosomal-recessive ciliopathic disorder affecting multiple organ systems. Characteristic features include progressive retinal dystrophy, obesity, polydactyly hypogonadism, mental retardation, and renal disorder…

Tightly focused linearly and radially polarized beam effect on the LSPR peak with varying particle size Open

Sarita, Rajan Jha, Rakesh Kumar Singh · 2023

Interactions of gold and silver spherical nanoparticles (NPs) of a wide range of radius size with tightly focused beams are investigated for a wide range of wavelengths. The scattering of tightly focused beams with a single NP of varying s…

Phase shifting to measure the modal composition of the scattered helical beam Open

Tushar Sarkar, Amit Kumar Singh Yadav, Tanushree Karmakar, Rakesh Kumar Singh · 2023

We propose and experimentally demonstrate a non-interferometric and highly stable technique to recover the incident orbital angular momentum (OAM) modes from the randomly scattered coherent light. To implement and demonstrate this techniqu…

Randomness assisted in-line holography with deep learning Open

Manisha, Aditya Chandra Mandal, Mohit Rathor, Zeev Zalevsky, Rakesh Kumar Singh · 2023

We propose and demonstrate a holographic imaging scheme exploiting random illuminations for recording hologram and then applying numerical reconstruction and twin image removal. We use an in-line holographic geometry to record the hologram…

Enhancing Phase Measurement by a Factor of Two in the Stokes Correlation Open

Amit Kumar Singh Yadav, Tushar Sarkar, Takamasa Suzuki, Rakesh Kumar Singh · 2023

Phase loss is a typical problem in the optical domain, and optical detectors only measure the amplitude distribution of a signal without its phase. However, an optimal phase is desired in a variety of practical applications, such as optica…

Poincare vector correlations to estimate polarization dynamics in the laser speckle Open

Sourav Chandra, Rajeev Singh, Rakesh Kumar Singh · 2023

We propose and experimentally demonstrate a new method to measure the spatial polarization dynamics of laser speckles. This is realized by using the concept of the Poincare vector correlations and experimentally measured Stokes parameters.…

Imaging Incoherent Target Using Hadamard Basis Patterns Open

Tanushree Karmakar, Rajeev Kumar Singh, Rakesh Kumar Singh · 2023

In this paper, we present a correlation-based imaging technique in a single-pixel imaging scheme using Hadamard basis illumination. The Hadamard basis, which has the characteristics of a two-bit value {−1, 1} and sparsity in its tran…

Randomness assisted in-line holography with deep learning Open

Manisha, Aditya Chandra Mandal, Mohit Rathor, Zeev Zalevsky, Rakesh Kumar Singh · 2023

We propose and demonstrate a holographic imaging scheme exploiting random illuminations for recording hologram and then applying numerical reconstruction and twin removal. We use an in-line holographic geometry to record the hologram in te…

Focused polarization ellipse field singularities: interaction of spin-orbital angular momentum and the formation of optical Möbius strips Open

S.K. Pal, Lavi Somers, Rakesh Kumar Singh, P. Senthilkumaran, Ady Arie · 2023

We study here the intensity distribution and formation of optical polarization Möbius strips by tightly focusing of C-point singularity beams. These beams are characterized by a central circular polarization point (C-point) surrounded by a…

Water Quality Assessment in Terms of Major and Minor Elements in Surface, Ground and Sea Water and Correlating the Presence with Associated Problems Open

Ajay Kumar, Rakesh Kumar Singh · 2023

The major and minor elements and their salts are the targeted investigation of surface water, ground water and sea water by the scientists worldwide. The presence of such elements depends on the nature of rock, soil, weathering phenomenon,…

Digital Fourier Transform Holography Using a Beam Displacer Open

Mohit Rathor, Shivam Kumar Chaubey, Rakesh Kumar Singh · 2023

Fourier transform holography overcomes the phase recovery challenge through recording complex field information of the object in an interference pattern recorded at the far field, i.e., Fourier plane. Moreover, this geometry helps to recon…

Holography with Incoherent Light Open

Akanksha Gautam, T S Athira, Dinesh N. Naik, C. S. Narayanmurthy, Rajeev Singh , et al. · 2023

Conventional digital holography uses the technique of combining two coherent light fields and the numerical reconstruction of the recorded hologram leads to the object amplitude and phase information. Despite significant developments in th…

Digital Polarization Holography: Challenges and Opportunities Open

Rakesh Kumar Singh · 2023

Polarization has a profound impact on image quality and visual perception. For instance, polarization provides a new perspective on seeing an object which is otherwise obscured, low contrast or not measurable by conventional imaging method…

A Compact and Lens Less Digital Holography Setup for Polarimetric Analysis of Spatial Light Modulator Open

Manisha Dixit, Vipin Tiwari, Nandan S. Bisht, Rakesh Kumar Singh · 2023

Ghost Diffraction Holography: A Correlation Assisted Quantitative Tool for Complex Field Imaging and Characterization Open

R. V. Vinu, Ziyang Chen, Rakesh Kumar Singh, Jixiong Pu · 2022

The fascinating domain of ghost imaging has been a subject of interest in the fundamental and applied research for the last two decades with its promising applications in various imaging and characterization scenarios. In this chapter, we …

Reconstructing complex field through opaque scattering layer with structured light illumination Open

Aditya Chandra Mandal, Manisha, Abhijeet Phatak, Zeev Zalevsky, Rakesh Kumar Singh · 2022

The wavefront is scrambled when coherent light propagates through a random scattering medium and which makes direct use of the conventional optical methods ineffective. In this paper, we propose and demonstrate a structured light illuminat…

Stokes correlation to estimate topological charge from the speckle pattern Open

Tushar Sarkar, Rakesh Kumar Singh · 2022

The orbital angular momentum (OAM) of the vortex or helical beam, connected with the topological charge (TC) of the beam, has been used as an alternative degree of freedom to encode and decode the information in the optical signals. Many d…

Ghost diffraction: A spatial statistical approach Open

Manisha, Vipin Tiwari, Nandan S. Bisht, Bhargab Das, Rakesh Kumar Singh · 2022

We report the reconstruction of a transparency image in Ghost diffraction scheme using a statistical optics approach. This is implemented by using a static diffuser rather than a pseudo thermal light source with a rotating diffuser. The ex…

Structured transmittance illumination coherence holography Open

Aditya Chandra Mandal, Tushar Sarkar, Zeev Zalevsky, Rakesh Kumar Singh · 2022

Focal intensity landscapes of tightly focused spatially varying bright ellipse fields Open

S.K. Pal, Rakesh Kumar Singh, P. Senthilkumaran · 2022

Vector vortex beams play an important role in tailoring tightly focused fields by creating an additional longitudinal component at the focal plane. Until now, mainly focusing properties of fundamental, higher order vector fields and negati…

Reconstructing Complex Field Through Opaque Scattering Layer with Structured Light Illumination Open

Aditya Chandra Mandal, Manisha Dixit, Abhijeet Phatak, Zeev Zalevsky, Rakesh Kumar Singh · 2022

Recovery and Characterization of Orbital Angular Momentum Modes with Ghost Diffraction Holography Open

Yanyan Huang, R. V. Vinu, Ziyang Chen, Tushar Sarkar, Rakesh Kumar Singh , et al. · 2021

Orbital angular momentum (OAM) of optical vortex beams has been regarded as an independent physical dimension of light with predominant information-carrying potential. However, the presence of scattering environment and turbulent atmospher…

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