The temperature on the busbars of electric generators in the end‐winding region needs to be monitored continuously. High temperature is associated with curvatures, seams, and poor ventilation. However, this solution has limitations, such as the number of measurement points. This article presents a reconstruction algorithm to estimate high‐resolution signals, from readings of a distributed temperature system for monitoring high‐power generator bars. The purpose of this work is to measure the temperature in the end‐winding region with optical sensors based on Raman distributed temperature sensing (RDTS). The ability of RDTS equipment to perform a measurement is limited by its spatial resolution of 1 m. The proposed algorithm reduces spatial resolution through signal processing without changing the equipment hardware. Through the experimental results, it was possible to perform accurate temperature measurements for lengths up to 15 cm using the sensor element. With this method, the final winding of a generator bar of a 355 MW hydroelectric plant was instrumented in the laboratory. The results show that it is possible to monitor the temperature over this region, which has a length of 45 cm. Therefore, the proposed method has the potential for the use of RDTS systems for temperature acquisition of small, medium, and large electrical machines.

In this study, we analyze the combined effect of TMD/Perovskite/2D Material on the performance of SPR biosensor using Kretschman configuration. In order to optimize the parameters, we compare the results of each material falls in the family of TMD/Perovskite/2D respectively and finally applied in the proposed sensor. It is observed that the combined structure based on black phosphorus, a 2D material, Barium Titanate (BaTiO 3 ) as a Perovskite material and Tungsten disulfide (WS 2 ) as a TMD material respectively shows excellent performance in terms of a performance parameter of the sensor. Incident light wavelength is fixed of 633 nm and radiative properties of a multi‐layered structure are calculated by transfer Metrix method. Essential performance parameters like Figure of Merit (FOM), Sensitivity, Detection Accuracy obtained by using the standard formula given in the paper. The reported figure of merit (FoM) and sensitivity are 62.51/RIU and 370. respectively. The results obtained in this paper expect to prove a significant role in the biosensing field like DNA hybridization as well as for the application of Perovskite materials in biosensing.

In the present paper, the bit error rate (BER) performance of hybrid power line communication (PLC) and multiple‐input multiple‐output (MIMO) visible light communication (VLC) system (HPMV) has been investigated using line‐of‐sight (LOS) and LOS plus first reflection (L‐R1) signals for room size of 5 m × 5 m × 3 m (configuration A) and 7.5 m × 7.5 m × 3.5 m (configuration B). In the work, Rayleigh fading and Barry channel models have been considered for PLC and VLC channels respectively. The BER has been analysed by varying separations between LEDs as 0.2 m, 0.6m and 1m for both configurations. The results show that the BER for LOS and L‐R1 signals decreases upto optimal separation of 0.6 m for configuration A. However, the result indicates that the required optimal separation for configuration B is more than configuration A. The channel frequency response of MIMO‐VLC and HPMV system has been inspected and it supports the results of BER simulation. It has been found that, with increase in spatial separation between LEDs, the deep notches and attenuation in the frequency response of MIMO‐VLC system decrease. The overall investigation shows that even though OFDM is resilient to frequency selective fading, an optimum separation between LEDs must be chosen according to the room size for the HPMV system.

This study accessed the performance of the four-level Manchester coding (4-MC) and four-level modified Manchester (4-MM) technique at the bit rates of 20 and 40 Gb/s for the first-order and second-order optical equalisers. The performances were evaluated with respect to bit error rate (BER), power penalty, eye diagrams, and dispersion tolerance. Based on the results by utilising the second-order optical equaliser, at 20 Gb/s, the transmission distance of 4-MC and 4-MM was extended by 25 and 27 km of standard single-mode fibre (SSMF), respectively, while at the bit rate of 40 Gb/s, the 4-MC and 4-MM transmission distance was extended by 6.5 and 7.5 km of SSMF, respectively. Hence, the second-order optical equaliser can adequately compensate for the fibre dispersion and consequently the overall BER performance. Therefore, the proposed system could serve as an alternative to the next-generation high-speed optical transmission links.

This study analysed GaN nanophosphors based white light‐emitting diodes (WLEDs) with ultraviolet (UV) excitation. Graphene quantum dots (GQDs) used as a charge transfer medium to enhance the performance in terms of luminous efficacy and colour quality. The improvement in colour rendering and colour temperature has been observed with the increase in injection current. The luminous efficacy of radiation also gets improved with injection current and maximises up to 255 lm/W at 260 mA along with 90 colour rendering index and 7100 K correlated colour temperature. Mapping of higher surface temperature for GQD‐based devices shows a better thermal stability, indicating the good heat dissipation capability of GQDs because of excellent thermal conductivity. Therefore, proposed WLEDs were found more competent with improved thermal quenching of phosphors for rare‐earth‐free solid‐state lighting as compared to the blue chip‐excited yellow phosphors.

In this work, the authors review different design setups of polarisation beam splitters (PBSs) developed in Si3N4 platforms. They analyse different approaches based on directional couplers and interferometers. Then the authors present the design and simulation results of a PBS based on two cascaded multi‐mode interferometers that operate in the whole C‐band. Finally, the authors compare the devices in terms of insertion loss, extinction ratio, bandwidth, footprint and fabrication tolerances.

This study has given the investigation for achievable net coding gain (NCG) of optical forward error correction (FEC) coding scheme with convolutional code to control the received sensitivity following a required signal-to-noise ratio in the communication channel. The achievable NCG is obtained from the difference between the upper bound NCG and the power penalty of the optical exclusive-OR (XOR) gate, which is based on a four-wave mixing in highly non-linear fibre. The upper bound NCG was analytically derived by calculating error probability of optimal convolutional code, and the power penalty was numerically derived by comparing bit-error rates between with and without the optical FEC coding. To confirm the feasibility for achieving the highest NCG, the optimal operating condition of the optical XOR gate is experimentally evaluated to minimise their power penalty. A 0.5 dB power penalty was obtained at BER = 10 − 9 under the optimised condition with 223−1 pseudo-random binary sequence differential phase-shift keying-modulated return to zero signal at 10 Gbps.

The authors present a new method for determining the optical properties of arbitrary refractive index elliptical core fibres. The method applies the elliptic cylindrical coordinate system to Maxwell's equations and appropriately, using Fourier Transforms, operated on an elliptical core optical fibre waveguide, derives a flexible algorithm, which can be used to determine the optical properties of elliptical fibre waveguides. By dividing the fibre into a series of uniform consecutive thin dielectric layers transversely across the elliptical cross section with suitable transforming functions representing voltage and current themselves based on the electromagnetic field components, leads to transverse transmission line equations. The resonance frequencies of the cascaded matrices determine the mode propagation constants. The analysis leads to a numerical algorithm for calculating the exact modes of propagation constants. The method is analytically exact and computationally accurate, leading to algorithmic implementation, without making use of Mathieu functions which are solutions for step index waveguide. The advantage of this work is also the fact that it can be applied to arbitrary refractive index profiles. They present results of modal diagrams for various fibre ellipticities and also apply this method to determine the birefringence of graded index profile fibres and mode cut‐off frequencies.