Titanium Diselenide (TiSe2) thin films have become attractive options for high-performance optoelectronic devices due to their exceptional optical and electronic properties and distinctive layered structure. However, despite their promise, TiSe2 has not been well explored for Photoelectrochemical photodetector applications, especially when it comes to improving its carrier dynamics, stability, and spectrum response under operating circumstances. Present article demonstrates significant advancement in the field by utilization of large area TiSe2 thin film for fabrication of high-performance photoelectrochemical photodetector (PEC-PD). Herein, TiSe2 crystalline powder is grown using direct vapour transport technique followed by elemental and morphological confirmation via Energy Dispersive X-ray Analysis and Field Emission Scanning Electron Microscopy that revealed layered hexagonal structure along with maintaining stoichiometry. From the grown compound of TiSe2, thin films are deposited by physical vapour deposition and well characterised. Powder X-Ray Diffraction analysis confirmed hexagonal structures whereas Raman spectroscopy identified the vibrational modes of TiSe2 in thin film. Atomic Force Microscopy portrayed surface smoothness along with uniformity. This large area TiSe2 thin film is utilised as working electrode in the application of PEC-PD that demonstrated optimum performance by achieving high detectivity of about 7.36 ± 0.02 × 108 Jones under low-power operation of 100 mV bias. The device indicated rapid photoresponse dynamics by exhibiting a rise and decay time of 12 ms and 33 ms respectively. To the best of our knowledge, this is the first report of a TiSe2 thin-film-based PEC-PD. Outcome of current study showcases the potential of TiSe2 in facilitating fabrication of high-performance optoelectronic devices.

Measuring refractive index values in transparent liquids has broad applications across industrial, scientific, and technological domains for their identification and characterization. Here a phase measuring deflectometry technique with an artificial fringe system is demonstrated to measure the refractive indices of transparent liquids. It works by projecting a line pattern displayed on a smartphone screen through a test chamber with a unique geometry containing the test solution, which a smartphone camera records. The technique detects changes in refractive index by analyzing phase changes resulting from fringe shifts due to the test solution. The phase difference is determined using Fourier transform-based fringe analysis, and the refractive index is measured by extracting features from the computed phase difference profile and training a regression machine learning algorithm. The developed system is compact, simple, low-cost and accurate. It can measure refractive index with a root mean squared error (RMSE) of 8.5375 × 10⁻⁴, a mean absolute error (MAE) of 7.9 × 10⁻⁴, and a precision of 3.175

This study demonstrates Phase Measuring Deflectometry (PMD) as an optical technique for visualizing heat flow and detecting thermal anomalies in metallic materials. Heat conducted from a thermally loaded sample into an adjacent transparent medium induces spatial refractive index gradients, which distort a projected fringe pattern. These distortions are captured and analysed using PMD, enabling emissivity-independent visualization of the heat flow field. Experimental results on aluminium and structural steel slabs reveal distinct phase signatures linked to thermal conductivity differences. The method offers a compact, non-invasive, and surface-independent alternative to conventional thermography, well-suited for engineering diagnostics and material evaluation.

Shape profiling and thickness information of living cells can provide critical insights about the cells, which can help in their identification and characterization. Most living cells are difficult to image as they are very small and almost transparent. In conventional bright-field microscopy, this issue is resolved by using staining agents, but they can potentially disrupt a cell's natural life cycle. Generally, to address this issue, quantitative phase contrast imaging, such as digital holography is employed, as it provides direct phase information. However, in some practical applications, employing the digital holography technique can become challenging due to stringent optical requirements and its high sensitivity to thickness change. Here, we present phase measuring deflectometry as a microscopy technique by employing a four-step phase-shifting method for shape visualization and thickness measurement of transparent micro-objects. The technique provides phase that is proportional to the deflection angle, which, in turn, depends on the gradient of the optical thickness of the sample. So, the system was calibrated using a 5 μm diameter transparent polystyrene microsphere. A scaling factor was determined by the calibration process, which was then tested by measuring the thickness of a 15 μm diameter transparent polystyrene microsphere. This result obtained with phase measuring deflectometry agrees with the digital holographic microscopy measurement. The proposed technique was further used for visualization and thickness measurement of the red blood cells (RBCs). Based on the available information, the presented technique and algorithm have not been previously exploited for shape visualization and thickness measurement of transparent micro-objects.

In order to protect the ocean ecosystem, the pursuit of sustainable and self-powered photodetectors is critical for revolutionizing underwater optical communication (UOC) used for environmental hazard sensing. This step enables energy-efficient and real-time detection of marine ecosystem threats such as chemical contamination, oil spill, and eutrophication. Although layered metal dichalcogenides (LMDCs) with exceptional optoelectronic properties and chemical stability are the most suitable materials, their integration into UOC technology remains largely unexplored. To address this, the present study demonstrates and evaluates seawater-immersed photoelectrochemical photodetectors (PEC-PDs) based on SnSe₂, an emerging member from the LMDC family. Direct vapor transport-grown SnSe₂is well characterized in its thin-film form by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and PL spectroscopy, followed by utilization as photoelectrodes in the PEC-PD devices. Fabricated PEC-PDs exhibit a responsivity of 505.74 ± 4.65 μA/W at zero bias and 10.34 ± 0.16 mA/W at 0.4 V bias; they outperform conventional Na₂SO₄-based devices by 21-fold and 82-fold, respectively. To the best of our knowledge, this is the first report presenting an SnSe₂-based PEC-PD utilizing seawater electrolyte and its performance evaluation. A proof-of-concept UOC demonstration of the present study paves the way toward the next-generation green optoelectronic devices for self-sustainable marine technologies.