We study chiroptical properties of single-layer dielectric membrane metasurfaces with broken in-plane symmetry. In sharp contrast to a common belief that chiral optical phenomena require symmetry breaking in the vertical direction, we show that flat single-layer metasurfaces are capable of strong specific chiral effects. Although the single-layer geometry forbids conventional co-polarized circular dichroism, strong resonant conversion circular dichroism appears to be possible in particular wavelength ranges determined by the spectra of photonic eigenmodes. We explore its origin starting with a C_4 rotation-symmetric and in-plane mirror-symmetric membrane metasurface and applying to it various in-plane perturbations. Simultaneously breaking of the in-plane mirror symmetry and lifting the rotation symmetry unlocks resonantly enhanced circular conversion dichroism. We derive selection rules for this effect and trace its origin to eigenmode interference and intercoupling using chiral coupled-mode theory.

Organic light emitting diodes (OLEDs) are evolving as nontraditional electronic devices owing to their mechanical flexibility, high visual quality, quick activation speed, and efficiency at low voltages and across wide temperature ranges. OLEDs have become widely used for display and lighting applications; however, they are now being used as sensors light sources, and light detectors for biomedical applications and early detection of disease. Advances in OLED design, architecture, device technology, and synthesis fabrication techniques have allowed for improvements in performance, durability, and utility. The article describes the various OLED design architectures, the individual layer function, and the individual layer materials responsible for charge conduction, exciton formation, and light emission. In addition, advances in fabrication processes, efficiency improvements, and life extensions of OLEDs have been identified, with consideration of future applications of OLEDs in organic thin film transistors, integrated optical sensors, and medical devices. Taken together, these perspectives present the current status of OLED devices, materials, and engineering techniques as well as future developments for OLEDs.

Whispering gallery mode (WGM) microdisk resonators are promising optical devices that confine light efficiently and enable enhanced nonlinear optical effects. This work presents a novel approach to reduce sidewall roughness in SiO2 microdisk resonators using focused ion beam (FIB) polishing. The microdisks, with varying diameter ranging from 5 to 20 mu m are fabricated using a multi-step fabrication scheme. However, the etching process introduces significant sidewall roughness, which increases with decreasing microdisk radius, degrading the resonators' quality. To address this issue, a FIB system is employed to polish the sidewalls, using optimized process parameters to minimize Ga ion implantation. White light interferometry measurements reveal a significant reduction in surface roughness from 20 nm to 7 nm for a 5 mu m diameter microdisk, leading to a substantial enhancement in the scattering quality factor (Qss) from 3 x 102 to 2 x 106. These findings demonstrate the effectiveness of FIB polishing in improving the quality of microdisk resonators and open up new possibilities for the fabrication of advanced photonic devices.

The realization of on-chip photonic circuits requires scalable and deterministic single-photon emitters (SPEs) at room temperature, which remain a challenge in van der Waals materials. In this work, we report a novel three-step fabrication process for the generation of spatially controlled SPE arrays in hexagonal boron nitride (hBN). The process comprises site-selective gallium (Ga) focused ion beam milling, nanoscale conformal carbon deposition over the patterned regions, and subsequent thermal annealing. The synergistic combination of these steps resulted in a site-correlated emitter yield of (∼ 89%) across 100 fabrication sites. Second-order autocorrelation measurements revealed pronounced three-level emitter dynamics where the best emitters exhibited high purity (g^(2)(0)=0.15 ± 0.09).To the best of our knowledge, this is the first lithography-free, direct-write approach combining Ga-ion milling, selective carbon engineering, and thermal annealing to deterministically generate s. The reproducibility of the method is validated across multiple independently fabricated samples. These results establish a scalable, lithography-free pathway toward on-demand SPE arrays relevant to integrated quantum photonics.

Soil Test Crop Response-based nutrient application is an important strategy for improving soil fertility, nutrient use efficiency, and sustainable wheat production in Agronomy. Inceptisols, widely cultivated for wheat, often face nutrient imbalances that limit productivity and soil health. A field experiment was conducted for two consecutive years during the Rabi seasons of 2020-21 and 2021-22, at Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj, District of Uttar Pradesh. The central objective of this experimentation was to evaluate the implications of employing a Soil Test Crop Response (STCR) strategy for fertilizer application and its chaser impact on soil attributes and yield within the background of Inceptisol soil order, with a focused attention on wheat (Triticum aestivum L.) cultivate within the Prayagraj region. Sandy loam in soil texture, belongs to soil order Inceptisol and neutral in soil reaction. Soil samples were taken from two depth viz.0-15 cm and 15-30 cm and analyzed for their physico-chemical properties (BD, PD, Soil pH, and OC). The experiment was carried out in Randomized Block Design and replicated thrice with 9 treatments. The best treatment combination was (T9) STB (100:75:50 NPK kg/ha + FYM 15 t/ha), which displayed grain yield of 6.50 t /ha on a pooled basis respectively. It is concluded that the advantageous use of NPK fertilizers with FYM- based organic fertilizer on STCR standpoint not only grant best wheat yield but also increased soil status and environment approachable.

Blue narrowband photodetectors are crucial for next-generation sensing applications such as imaging, health monitoring, and environmental detection. Outstanding optoelectronic characteristics and bandgap tunability make perovskites prime candidates for realizing narrowband photodetection. In this work, we fabricated a self-powered blue narrowband photodetector based on a mixed-cation perovskite (FA(0.9)Cs(0.1)PbI( 3)) using a photon-field modulation approach. The detector exhibited a response peak at 490 nm, with a full-width at half-maximum of 77 nm, along with a detectivity of 10(10) Jones. The detector also showed a rise time (t(r)) of 318 ms and a fall time (t(f)) of 286 ms under 490-nm illumination, and stable performance up to 38 days without encapsulation. This study demonstrates stable blue narrowband photodetection suitable for low-power integration into imaging and optoelectronic systems.

Organic Thin-film transistor (OTFT) has many merits because of their numerous properties, such as affordable low-cost manufacturing, mechanical-flexibility and widely used in smart sensors and displays. This research paper provides brief analysis and discussion of key influencing-factors that predict the OTFT performance. Besides this, commonly used material is also presented for wide range of applications including material properties, characterises and stability. In this, behaviour indicators like Mobility, Sub-Threshold Slope, ION/IOFF ratio, Threshold-voltage also described. Additionally, this paper also offers a brief overview of inverter technology driven by OTFT. This paper will be useful for readers who are beginners in the field of OTFT.

Organic light-emitting diodes (OLEDs) have emerged as a promising technology in optoelectronics, distinguished for their flexibility, lightweight design, and cost-effectiveness. This comprehensive review delves into the intricacies of OLED technology, focusing on small molecule OLEDs (SM-OLEDs), polymer OLEDs (PLEDs), and emerging innovations in the field. By elucidating OLED performance fundamentals, the article offers a detailed comparison of different types of OLEDs, highlighting their unique strengths and applications. Beyond technical considerations, the review explores practical applications that show-case the transformative potential of OLEDs across various industries. From vibrant displays to energy-efficient lighting solutions and the burgeoning field of wearable electronics, OLEDs are poised to revolutionize user experiences and functionality. By providing insights into the current state of OLED research and development, this article serves as a guiding beacon for both researchers and enthusiasts seeking a deeper understanding of this cutting-edge technology. Whether exploring OLED performance intricacies or envisioning its diverse applications, readers will find this review to be an invaluable resource in navigating the dynamic landscape of optoelectronics.

Controlling optical chirality at the subwavelength scale is essential for applications of nanophotonic structures in polarization optics, sensing, and nonlinear photonics. Achieving a strong chiroptical response in planar dielectric metasurfaces without intrinsically chiral meta-atoms remains challenging. A recent study proposed a novel mechanism of metasurface chirality and predicted that bilayer metasurfaces with rotated C4-symmetric apertures can exhibit a chiral response originating from resonant chiral photonic modes. Here, we experimentally confirm this concept by demonstrating resonantly enhanced circular dichroism in the near-infrared. We fabricated a free-standing silicon membrane metasurface that is nominally achiral. Breaking the out-of-plane symmetry with a thin PMMA layer unlocks and activates a strong chiral response. The observed circular dichroism is governed by chiral photonic modes, interlayer coupling, and symmetry breaking, in agreement with theoretical predictions. These results establish bilayer metasurfaces as a simple and versatile platform for engineering strong mode-induced chirality in compact planar photonic metadevices.

Ovum pick-up (OPU) is a transvaginal ultrasound-guided technique used for repeated follicular aspiration and in vitro embryo production in cattle. Procedural variables such as needle gauge, aspiration pressure, flow rate, follicle size, synchronization strategy, and temperature influence oocyte recovery and cumulus–oocyte complex (COC) integrity. This study describes validation of a standardized OPU preset in cyclic, non-stimulated Tharparkar (Bos indicus) cows. Clinically healthy cyclic cows were screened by gynaecological examination and ultrasonography. Dominant follicle ablation (≥9 mm) was performed to synchronize a new follicular wave. OPU was conducted on Days 4–7 post-ablation during early follicular recruitment. Procedures were standardized, including uniform restraint, caudal epidural anesthesia (4–5 mL of 2% lignocaine), aseptic preparation, and single-operator execution. Follicles measuring 3–9 mm were aspirated using an 18-gauge disposable needle connected to a regulated vacuum system. Refinement observations identified an optimal aspiration pressure of 80–85 mmHg with a controlled flow rate of ~15 mL/min. Higher pressures (85–90 mmHg) increased COC denudation, whereas lower pressures (70–80 mmHg) reduced follicular evacuation efficiency. Collection media were maintained at 38.5°C throughout. A total of 210 follicles yielded 118 oocytes, with an overall recovery rate of 56.08 ± 3.27%. Mean follicles aspirated and oocytes recovered per session were 21.0 ± 0.81 and 11.8 ± 0.87, respectively. Morphological grading revealed 32.09 ± 4.27% Grade A, 27.77 ± 3.90% Grade B, 17.15 ± 3.52% Grade C, and 23.00 ± 5.24% Grade D oocytes, with 59.86 ± 3.11% classified as acceptable (Grade A+B). The defined preset enabled consistent follicular aspiration and stable oocyte recovery, supporting a reproducible, breed-adapted OPU protocol for indigenous Bos indicus cattle."

Sexed semen technology has emerged as an important reproductive tool for improving genetic progress and herd structure in dairy production systems. Field performance of sexed semen artificial insemination was evaluated in cattle (n = 840) and buffalo (n = 319) under smallholder dairy systems in Bareilly district, India. Pregnancy diagnosis at 80–90 days post-insemination revealed an overall conception rate of 46.7% in cattle (392/840) and 44.3% in buffalo (141/319), indicating moderate yet field-relevant fertility outcomes. In cattle, breed exerted a highly significant effect on conception (χ² = 21.07, df = 2, p < 0.0001), with indigenous animals showing superior fertility (52.1%; 294/564) compared to crossbred (37.3%; 59/158) and exotic animals (33.1%; 39/118). Odds ratio analysis confirmed higher likelihood of conception in indigenous cattle relative to crossbred (OR = 1.83; 95% CI: 1.28–2.62). Parity-wise analysis demonstrated peak fertility in mid parity animals (50.6%; 160/316), followed by heifers (46.0%; 23/50), early parity (44.7%; 168/376) and high parity animals (41.8%; 41/98). Interaction analysis highlighted the highest conception in indigenous mid parity animals (62.2%), indicating a strong combined effect of genetic adaptability and physiological maturity. Buffalo exhibited comparable conception; however, absence of detailed subgroup data restricted further evaluation. In conclusion, sexed semen represents a practical and effective reproductive strategy under smallholder dairy systems, enabling acceptable fertility outcomes while facilitating genetic improvement and targeted female calf production, with optimal results achieved in indigenous cattle and mid parity animals under field conditions. However, lack of calf sex ratio data at the time of analysis, incomplete recording of breed and parity in buffalo, variability in smallholder management practices and farmer-based estrus detection, absence of quantitative assessment of body condition, nutrition and environmental stress, and restriction to a specific geographical region may limit comprehensive evaluation and broader applicability of the findings.

Color-selective photomultiplication-type photo detectors play a vital role in the design of image sensors, secured optical communication systems, and machine vision with low-power light detection ability. In this study, we demonstrate a fully vacuum-processed narrowband organic photodetector (OPD) based on boron subphthalocyanine chloride (SubPc) as the active layer and zinc phthalocyanine (ZnPc) as an optical filtering layer. The final device showed a narrowband response centered around 500 nm with a full width at half maximum (FWHM) of 68 nm, a high responsivity (R) of 5.21 A/W and an external quantum efficiency of 1292% at -8 V bias.

In this work, a nanocomposite using ZnTCPP MOF and ZnO nanoparticles is synthesized. A broadband photodetector is optimized using this nanocomposite to enhance the performance of a photomultiplication-based organic photodetector. Various weight percentages (w/w%) of ZnO were incorporated in the ZnTCPP metalorganic framework precursor during synthesis, and material parameters were analyzed via structural and chemical analysis methods. These nanocomposites were incorporated in the P3HT:PCBM matrix in a 1:1:0.5 wt ratio, and photodetectors were fabricated with an inverted structure (ITO/TiO2/Active Layer/Al). A reference device with P3HT:PCBM and ZnO nanoparticles is fabricated and compared. Photomultiplication is observed in all the devices, with the devices with nanocomposite showing enhanced quantum efficiency and responsivity. The best-performing ZnTCPP@ZnO-based device reported the highest EQE of 10827 % at 510 nm for a given bias of -5 V. Photomultiplication is attributed to the trap states created due to the TiO2/active layer interface and the presence of ZnO in the active material. ZnO acts as a hole-blocking component, giving rise to charge accumulation and, subsequently, tunneling electrons. These devices have shown high responsivity (44.53 A/W), small rise time/fall time (61.7 ms/107.6 ms), and high detectivity (7.2 x 1011 Jones) at a given bias voltage of -5 V.

We study the behaviour of edge states in Rice-Mele model with Hubbard interaction, U , at half-filling using density matrix renormalization group, exact diagonalization and effective charge dynamics in Kumar representation. For a fixed dimerization, δ, and staggered potential, V , we find by increasing U the quasiparticle edge states in the charge gap to come down in energy from V in the absence of Hubbard interaction to zero energy for U ≈ 2V . This presents an uncommon case where repulsion leads to zero-energy edge states. Upon increasing U further, the edge state energy starts increasing again until they are lost in the bulk. However, upon increasing U even further, these edge states reappear in the high energy gap. So, with Hubbard interaction, the edge states in Rice-Mele chain transmigrate from the physical charge gap to a high energy gap.