Double Pulse Research Articles

Target edge extraction for array single-photon lidar based on echo waveform characteristics

The target edge contains the shape and structure information of the target. Accurate extraction of target edges is the basis of target recognition and location. The number of pixels and signal-to-noise ratio severely limit the edge extraction capability of single-photon lidar. In this work, a target edge extraction algorithm for array single-photon lidar is proposed based on the distribution characteristics of the target edge echo waveform. The algorithm does not need to image the target or rely on the fixed direction edge detection template. The target edge is divided into the inside and outside edges based on the established target edge echo signal model of array single-photon lidar. Single and double Gaussian function fitting is used to extract the outside edge whose echo waveform is a double pulse distribution. The feature vector composed of skewness, FWHM, and total detection probability of the echo waveform is weighted K-means clustered to extract the inside edge whose echo waveform is a single pulse distribution. Screening misjudged pixels based on the Jensen-Shannon divergence between echo waveforms of each pixel to improve the edge extraction accuracy. Simulation and experimental results demonstrate that the proposed algorithm can extract target edges more completely and accurately than traditional edge extraction methods. The minimum inside edge depth of the target that the proposed algorithm can extract is cτ/2, where τ is the standard deviation of the emitted Gaussian laser pulse. This research has the potential to improve the target detection and recognition capabilities of array single-photon lidar.

Modelling and mitigating oscillation in E-mode GaN HEMT: A simulation-based approach to parasitic inductance optimization

The escalating demands in energy conversion necessitate the evolution of efficient power electronic devices beyond the limitations of traditional silicon (Si) counterparts. This research delves into the intricacies of the Enhancement mode Gallium Nitride High Electron Mobility Transistor (E-mode GaN HEMT). A focus is placed on its static characterization, parameter analysis, and the influence of external parasitic inductances, particularly regarding oscillation challenges during its hard switching process. Forward and revise bias are conducted through comparison with Si-MOSFET and Cascade-GaN HEMT, along with its static on-resistance and transfer characteristics. Through rigorous half-bridge double pulse circuit LTSPICE simulations, this study deciphers the turn-on and turn-off dynamics of the E-mode GaN HEMT. By scrutinizing various parasitic inductances, the research elucidates mechanisms instigating high-frequency voltage and current oscillations. Significantly, the research presents a hierarchy of parasitic inductance influences, employing an energy loss comparison. This analysis underscores the prominent impact of the common source parasitic inductance, which exhibits energy loss increases of 23.6 % and 22.7 % at junction temperatures of 25 °C and 75 °C, respectively. Building on these insights, the study recommends strategies to mitigate the effects of external parasitic inductance, underscoring the pivotal role of oscillation suppression in advanced GaN Printed Circuit Board (PCB) and Integrated Circuit (IC) designs. This comprehensive inquiry provides a blueprint for enhancing GaN circuit designs, paving the way for their optimal application in the evolving realm of power electronics.

Multipulse operation in Mamyshev oscillator: influence of external seed source

We study the influence of an external seed source on the startup of a fiber Mamyshev oscillator (MO). Depending on the seed source parameters, while keeping MO parameters fixed, we observe diverse mode-locked operations from the MO, generating stable single, double, triple and even up to a group of seven pulses. The probability of the occurrence of such mode-locked operations is studied. There can be different operating regimes in a particular multipulse operation. We find that there is an optimum spectral width of the seed source for which the probability of generating mode-locked stable train of single pulses from a fiber MO is maximum. Further, we find that the power of the seed source has less influence on the mode-locking state of the fiber MO; however, the probability of single or double pulse operation is relatively higher than that of multipulse operation at higher power of the seed source. These experimental observations will enrich the database of multipulse patterns and help in understanding pulse dynamics in the fiber MO. Suitably chosen seed source parameters can generate the desired pulse pattern. Such tailored outputs could have prospective applications in laser micromachining and high bit rate data transfer in optical networks.

Investigation of dynamic ron stability and hot electrons reliability in normally-off AlGaN/GaN power HEMTs

The current collapse and hot electron effect of 100 V normally-off GaN power HEMTs are investigated. The 100 V GaN-on-Si power HEMTs are fabricated on an industrial 200 mm Si CMOS compatible technology platform. The double pulse test (DPT) and the dynamic high temperature operating life (DHTOL) test are implemented to verify the dynamic on-resistance (dynamic Ron) stability. Wafer level hot electron reliability test is performed to investigate the effect of high electric field and high current on GaN power HEMT. It is proved that the dynamic Ron stability of 100 V GaN power HEMT is qualified (Ron/Rini, static < 1.2) when the drain-source off-state voltage (Vdsoff) is less than 80 V. It is shown that the dynamic Ron degradation of GaN device is recoverable by means of annealing. Hot electrons reliability is dominated by the high electric field at drain edge and the high current which is source injected electrons flowing to the drain. It is demonstrated that the Vth drift and Ron degradation are extraordinary serious under semi on-state stress condition with Vdsoff = 60 V.

Terahertz radiation from shockwave front irradiated with femtosecond optical pulses

AbstractFemtosecond double optical pulse experiments with nanosecond time delay were conducted in air. Terahertz pulses were generated from laser plasmas produced by the irradiation with the main pulses on shockwave excited by the pre‐pulse illumination. Intensity of the terahertz pulses depends on the time difference Δt and relative position Δy between the pre‐ and main pulses. We found a characteristic dependence of the intensity of the terahertz pulses on Δy at a longer time delay, Δt = 14.7 ns, which has two maxima while only one maximum was observed when delay times were at and shorter than 9.7 ns. The results are discussed taking into account air density distribution of the shockwave. The terahertz emission spectroscopy shown here can be a useful technique for investigating density structure and its time variation of shockwave with high temporal resolution.

604 nm&amp;639 nm Dual-wavelength double pulse Pr:YLF laser

A theoretical model of dual-mode rate equation has been developed to accurately describe the oscillation mechanism of a visible dual-wavelength double pulse Pr:YLF laser. The insertion angle of F-P etalon and the two-step loss of Q-switching are found to be critical factors in controlling dual-wavelength intensity ratio and master–slave pulse energy ratio. Experimental results demonstrate that tuning these parameters enables the production of a dual-wavelength double-pulse laser, with a maximum output power of 98mW, a pulse width of 100 ns, and a PRF of 10 kHz. To the best of our knowledge, this is the first investigation of a visible dual-wavelength double pulse Pr:YLF laser.

Generating Angular-Varying Time Delays of THz Pulses via Direct Space-to-Time Mapping of Metasurface Structures.

We experimentally demonstrate the generation of double terahertz (THz) pulses with tailored angular-dependent time delays from a nonlinear metasurface excited by a near-infrared femtosecond pulse. The tailored temporal properties of the generated pulses emerge from a direct mapping of the nonlinear spatial response of the metasurface to the emitted THz temporal profile. We utilize the Pancharatnam-Berry phase to implement symmetric and antisymmetric metasurface configurations and show that the emitted patterns present spatiotemporal "X-shaped" profiles after collimation by a parabolic mirror, with angular-dependent pulse delays corresponding to the intended design. In addition, we show that the addition of polarization multiplexing presents the opportunity to achieve a full range of elliptical THz polarizations. Double pulse generation and spatiotemporal shaping of THz waves in general show potential for THz spectroscopy and molecular dynamics applications, particularly in pump-probe experiments.

Chemically-stable flexible transparent electrode: gold-electrodeposited on embedded silver nanowires

Silver nanowires (AgNWs) with a low diameter, high aspect ratio, stable suspension, and easy synthesis have recently attracted the optoelectronic industry as a low-cost alternative to indium tin oxide transparent conductive films. However, silver nanowires are not chemically stable, and their conductivity diminishes over time due to reactions with atmospheric components. This is a bottleneck for their wide industrial applications. In this study, we aim to address this issue by synthesizing silver nanowires with an average diameter of approximately 65 nm and a length of approximately 13 µm. The prepared Ag nanowires are then applied to fabricate transparent, flexible, and chemically stable conductive films. The fabrication includes spraying of silver nanowires suspension on a glass substrate followed by Dr. blade coating of polystyrene (PS) solution and delamination of the PS-AgNWs film. The resulting film exhibits an optimum sheet resistance of 24 Ω/□ and transmittance of 84%. To further enhance the stability of the transparent conductive film, the facial and scalable double pulse electrodeposition method is used for coating of gold on the exposed surface of the AgNWs embedded in PS. The final transparent film with gold coating demonstrates a remarkable stability under harsh conditions including long exposure to UV light and nitric acid solution. After 100 min of UV/Ozone treatment, the increase in sheet resistance of the optimal PS-AgNW@Au sample is 15.6 times lower than the samples without gold coating. In addition, the change in sheet resistance after 2000 bending cycles in the optimal PS-AgNW@Au electrode is measured and it showed an increase of only 22% of its initial sheet resistance indicating its good flexibility. The proposed electrode performs an excellent chemical stability, good conductivity, transparency, and flexibility that makes it a potential candidate for various optoelectronic devices.

Photoelectric biomemristors for artificial visual perception systems

The redundant information generated by traditional image sensors causes a large amount of energy waste, which can no longer meet the needs of the rapid development of current artificial intelligence. Therefore, it is urgent to develop visual bionic systems with perception, memory and processing functions. Photoelectric memristors based on graphene quantum dots (GQDs) and the body fluid of Bombyx mori (BM) were fabricated, which can change its storage state when triggered by optical or electrical signals, and synaptic characteristics such as multilevel data storage, synaptic potentiation and synaptic depression were realized. The Boolean logic "OR" operation, the enhancement/inhibition of the synapse under the light signal and the double pulse dissimilation behavior are realized by UV light-driven resistance variable memory. The results show that photoelectric memristors have attractive biological applications in information perception, storage and computation and provide a potential method for the next generation of artificial visual perception systems.

Arterial hypertension and stiffness in women of different age groups and reproductive status

Objective: study of the relationship between arterial hypertension and arterial stiffness in women to identify potential markers of target organ damage and therapeutic targets of antihypertensive therapy.Materials and methods: the study involved 161 women who were divided into three groups depending on age and reproductive function. Group 1 consisted of 52 women aged 18 to 30; group 2 – 54 women aged 31 years before menopause; 3rd group – 55 women in the postmenopausal period. All women were questioned, clinical examination, determination of anthropometric data, measurement of carotid-femoral pulse wave velocity, determination of arterial stiffness by volumetric sphygmography, 24-hour blood pressure monitoring with assessment of aortic stiffness and characteristics of the central pulse wave.Results: 24-hour blood pressure monitoring revealed arterial hypertension in 38 (34,8%) women: 15 (27,8%) women in the 2nd group and 23 (41,8%) women in the 3rd group. Correlation analysis revealed the most significant correlations between the presence of arterial hypertension (R=0,45-0,71; p&lt;&lt;0,01) with central aortic pressure, double product index and average daily aortic pulse wave velocity in the aorta (PWVao), regardless of the state reproductive function. For women of reproductive age with arterial hypertension, the ambulatory vascular stiffness index (AASI: R=0,36; p=0,01) is more significant, while in the menopausal period, the arterial stiffness index (ASI: R=0,33; p=0,01). Correlation analysis did not reveal significant relationships between carotid-femoral pulse wave velocity and cardio-ankle vascular index (CAVI) with arterial hypertension in women of the 2nd and 3rd groups. The relationship between carotid-femoral pulse wave velocity and arterial hypertension in women was confirmed by analysis of variance (p=0,007).Conclusion: Central aortic pressure, carotid-femoral pulse wave velocity, AASI, ASI, PWVao – direct and indirect indicators of arterial stiffness – are interconnected with the presence of arterial hypertension in women of reproductive and menopausal age. In this regard, these indicators are potential markers of target organ damage in arterial hypertension.

Double pulse gas metal arc welding process parameter optimization and weld performance analysis based on response surface method

Double pulse gas metal arc welding (DP-GMAW) is a low-frequency modulated high-frequency pulse welding, which can fully stir the molten pool, and improve the forming and performance of the weld. In this study, a mathematical model was developed using the response surface method (RSM) with three main process parameters (welding current, peak-to-base ratio, welding speed) as input values with three key geometric characteristics parameters, and the mechanical properties of the resulting welds were investigated. The results showed that the parameter model developed in this study had less error and could optimize the process parameters better; the optimal process parameters (welding current, peak-to-base ratio, welding speed) were 160 A, 39.93%, and 83.11 cm min−1, respectively. The improved welding parameters result in better mechanical properties and better weld profile, and more stable welding process. As a result, this experiment provides a new perspective for process parameter optimization and mechanical properties research for weld manufacturing.

The design considerations of stray inductance for power modules with parallel-connected IGBT chips for a digital gate driver control

This paper aims to clarify the effect of asymmetric gate inductance Lg and emitter inductance Le inside power modules with two parallel-connected IGBTs on switching characteristics when a three-step digital gate driver is employed. Five types of IGBT modules with different Lg and Le were fabricated to implement double pulse tests by conventional gate driving and digital gate driving with three-step vectors. Under the conventional gate driving, the asymmetric Le introduced an imbalanced current during on-stage, and the asymmetric Lg introduced gate voltage spike Vg_spike and an imbalanced current during the turn-off interval. Large Lg introduced large Vg_spike. From the miller plateau in the turn-off, the current started to concentrate on the IGBT whose Lg is small. In the turn-on interval, the asymmetric Le made current share in two IGBTs become imbalanced, and the occurred large Vg_spike is positively corresponding to the difference of emitter current Ie flowing through two IGBTs. Under digital gate driving, it was found that the tradeoff between switching loss and voltage/current overshoots can be improved. And, the difference of Eoff between two IGBT chips, which results from asymmetric Le mainly, could be decreased more than that in conventional gate driving. In the turn-on interval, the large Vg_spike can be suppressed by a small vector number at the second step, and the difference of turn-on loss Eon could be also decreased. According to the above switching characteristics, the design considerations of power modules with parallel-connected IGBTs were proposed as the digital gate driver is applied.

Fast pulsed electrodeposition of silver nanoparticles on polypyrrole thin films for antibacterial and biomedical applications

This research paper presents a fast method for the double pulse electrodeposition of silver nanoparticles on a thin polypyrrole film with a thickness of about 4 µm, aiming to improve its electrical conductivity and antibacterial activity for biomedical applications. The electrodeposition and the electrochemical behavior of the deposits was studied using chronoamperometry and electrochemical impedance spectroscopy. SEM and XRD were used to characterize the morphological and microstructural characteristics of the deposits. The antibacterial performances of the deposits were tested against E.coli and S.aureus bacteria. It was found that the AgNO3 concentration of 10−2 M and/or the duration of the two pulses (1 s and 10 s) led to the deposition of micrometric or submicrometric Ag particles inhomogeneous in size and distribution on the PPy surface. The lower AgNO3 concentration (10−3 M) and the shorter pulse durations (0.1 s and 1 s) resulted in nanometric Ag particles with the most homogeneous size and distribution on the PPy surface. Furthermore, the Ag nanoparticles on PPy surface showed the highest electrical conductivity and the strongest killing efficiency of the two types of bacteria (100% against E.coli and 99.99% against S.aureus).

Experimental study on the ablation of stainless steel using multiple ultra-short laser pulses with tunable time delays

Results on the ablation of stainless steel using ultra-short single, double and quadruple pulses as a function of the fluence and the time delay between each laser pulse are presented. The investigations focused quantitatively on the ablated volume and the resulting ablation efficiency, and qualitatively on the topography of the structures produced, providing insights about physical mechanisms such as shielding, re-deposition of ablated particles, and accumulation of heat or energy. The results indicate a significant influence of fluence in combination with the time delay on the ablation process and the resulting ablation topography.

Modulation of ipsilateral motor evoked potentials during bimanual coordination tasks.

Ipsilateral motor evoked potentials (iMEPs) are difficult to obtain in distal upper limb muscles of healthy participants but give a direct insight into the role of ipsilateral motor control. We tested a new high-intensity double pulse transcranial magnetic stimulation (TMS) protocol to elicit iMEPs in wrist extensor and flexor muscles during four different bimanual movements (cooperative-asymmetric, cooperative-symmetric, non-cooperative-asymmetric and non-cooperative-symmetric) in 16 participants. Nine participants showed an iMEP in the wrist extensor in at least 20% of the trials in each of the conditions and were classified as iMEP+ participants. iMEP persistence was greater for cooperative (50.5 ± 28.8%) compared to non-cooperative (31.6 ± 22.1%) tasks but did not differ between asymmetric and symmetric tasks. Area and amplitude of iMEPs were also increased during cooperative (area = 5.41 ± 3.4 mV × ms; amplitude = 1.60 ± 1.09 mV) compared to non-cooperative (area = 3.89 ± 2.0 mV × ms; amplitude = 1.12 ± 0.56 mV) tasks and unaffected by task-symmetry. The upregulation of iMEPs during common-goal cooperative tasks shows a functional relevance of ipsilateral motor control in bimanual movements. The paired-pulse TMS protocol is a reliable method to elicit iMEPs in healthy participants and can give new information about neural control of upper limb movements. With this work we contribute to the research field in two main aspects. First, we describe a reliable method to elicit ipsilateral motor evoked potentials in healthy participants which will be useful in further advancing research in the area of upper limb movements. Second, we add new insight into the motor control of bimanual movements. We were able to show an upregulation of bilateral control represented by increased ipsilateral motor evoked potentials in cooperative, object-oriented movements compared to separate bimanual tasks. This result might also have an impact on neurorehabilitation after stroke.

Chaos Synchronization of InGaAsP Lasers

The optical output of a semiconductor laser can fluctuate chaotically by modulating its direct current in limited conditions of the modulated current signal parameters in terms of modulation frequency and modulation index. In this work, single, double, and chaotic pulses of an InGaAsP laser with direct current modulation, are numerically presented through a bifurcation diagram. Numerically, the unidirectional optical coupling system realizes chaotic synchronization between two identical InGaAsP lasers with direct current modulation, as the transmitter/receiver configuration. The transmission time for transmitting light from the transmitted laser to the received laser is essential for controlling the quality of chaos synchronization. The transmission time applies on the order of nanoseconds. Chaos synchronization quality is estimated by a correlation plot and calculated by the cross-correlation coefficient. This study observed the best synchronization quality (complete chaos synchronization) when the two lasers are identical. On the other hand, the chaotic synchronization between two non-identical InGaAsP lasers was investigated. In this case, complete chaos synchronization is not found, and the quality of chaotic synchronization was observed to decrease as the mismatch between the parameters of the two lasers increased.

Ultrafast control of laser-induced spin-dynamics scenarios on two-dimensional Ni3@C63H54 magnetic system.

The concept of building logically functional networks employing spintronics or magnetic heterostructures is becoming more and more popular today. Incorporating logical segments into a circuit needs physical bonds between the magnetic molecules or clusters involved. In this framework, we systematically study ultrafast laser-induced spin-manipulation scenarios on a closed system of three carbon chains to which three Ni atoms are attached. After the inclusion of spin-orbit coupling and an external magnetic field, different ultrafast spin dynamics scenarios involving spin-flip and long-distance spin-transfer processes are achieved by various appropriately well-tailored time-resolved laser pulses within subpicosecond timescales. We additionally study the various effects of an external magnetic field on spin-flip and spin-transfer processes. Moreover, we obtain spin-dynamics processes induced by a double laser pulse, rather than a single one. We suggest enhancing the spatial addressability of spin-flip and spin-transfer processes. The findings presented in this article will improve our knowledge of the magnetic properties of carbon-based magnetic molecular structures. They also support the relevant experimental realization of spin dynamics and their potential applications in future molecular spintronics devices.

Bottom-up Filling of Nanosized Trenches with Silver to Fabricate Transparent Conducting Electrodes

Transparent conducting electrodes (TCEs) are essential in many optoelectronic devices including solar cells, sensors, displays, and LEDs. The use of transparent metal oxide layers, in particular Indium tin oxide (ITO), is the most common used approach. However, ITO comes with numerous drawbacks such as the relatively rarity of indium and hence high cost, fragility, strong UV absorption and relative high sheet resistance. An exciting alternative TCE is the use of interconnected metallic nanowires, where their sub-wavelength cross-sections makes them transparent to visible light, where especially silver nanowires are a good candidate because of their high conductivity.Here we show a promising cost-effective method called selective-area electrochemical deposition (SAEC) for the fabrication of these metal nanostructures. SAEC is based on a through-the-mask electrochemical deposition method, where the mask is made using substrate conformal imprint lithography. Next to the inherent low fabrication cost of the electrochemical deposition, it has numerous advantages such as bottom-up growth, scalability, operate at ambient conditions, control over nucleation, and yields high purity deposits. While submicron sized features have been already demonstrated by SAEC, obtaining homogeneous void free filling of features below 100 nm using direct plating is a major challenge because of the terminal effect and the poor control of nucleation of the seed layer.In this work, we have explored the SAEC fabrication of large area silver nanowire grids on ITO substrates and on TOPCon solar cells. We show that the nucleation density of the silver nanoparticles is the key parameter for the successful homogenous void-free filling of the trenches. The nucleation density namely determines the coalescence thickness, which sets a minimum thickness for the silver nanowires in order to be connected. We control the nucleation density of the silver nanoparticles by making use of the double pulse method, where a high overpotential nucleation pulse is applied for controlling the nucleation density. After nucleation, we merge the silver nuclei by applying a low overpotential growth pulse.After the successful filling of the trenches, we have compared the optical and electrical performance of the SAEC fabricated silver nanowire grids to those using conventional thermal or e-beam evaporation followed by lift-off. The SAEC-fabricated TCEs show high transmission (>96%) and extreme low resistance (as low as 3 Ω/sq), resulting into a superior figure of merit (FoM). Due to the bottom-up nature of this technique, arbitrary high aspect ratio nanowires can be achieved and therefore the relationship of decreasing transmission with decreasing sheet resistance is broken.Furthermore, we have also incorporated the silver NW grids in TOPCon cells and compared the performance to similar cells based on ITO. This work represents a low-cost and scalable strategy to fabricate sub 100 nm predefined metal structures, enabling the commercial viable fabrication of nanostructure based transparent conductive electrodes for optoelectronic devices.

Influence of the Crystallographic Texture of ITO on the Electrodeposition of Silver Nanoparticles

Metal nanoparticles exhibit physical and chemical properties that differ significantly from macroscopic metal phases. In particular, silver nanoparticles (NPs) had have extensive attention since it has a strong interaction with light due to their high quality localized surface plasmon resonances, which can be tuned all across the visible to the NIR regime. These strong and tuneable interaction of visible light with silver NPs have found many applications, in sensing, surface enhanced Raman spectroscopy, photo(electro)catalysis, and more.Polycrystalline indium tin oxide (ITO) films are highly desired substrates for many of these optoelectronic applications. In many of these applications, it is essential to reliably and precisely control the size and density of silver NPs. Even though it is well known that the electrochemical control over nucleation and growth of silver NPs on foreign substrates highly depends on the surface properties of the substrate, yet, the only parameter that is often specified for these ITO substrates is a bulk property: sheet resistance. As a result, nucleation and growth on ITO is highly irreproducible.In this work, we show that ITO substrates with same technical specifications (i.e. sheet resistance, light transmittance and roughness) and supplier may still have different surface properties such as the crystalline texture. We find that these differences in the surface properties has a strong impact on the nucleation and growth. Even though we used seemingly equal ITO substrates, XRD and EBSD scans clearly differentiate between two types of films based on the ratio between the (222) and (400) related peaks. We controlled the density and size of the silver NPs by making use of the double pulse technique. In this method, where the high overpotential nucleation pulse controls the nucleation density. Previous studies have reported an empirical exponential relationship between island density and nucleation pulse overpotential, where the slope is a measure for the electron kinetics.We find that the preferential presence of lower index surfaces (e.g. (100)) leads to few orders of magnitude lower particle density compared to the preferential presence of higher index surfaces (e.g. (111)). Furthermore, the density on the lower index surface is strongly dependent on the nucleation pulse overpotential, while the higher index surface is barely affected. We find that this difference in the relationship is caused by mass transport limited nucleation. We have verified this through a spatial correlation analysis using the nearest-neighbour distance. For higher index surfaces, the nucleation density is already large compared to the Nernst diffusion length at low nucleation pulse overpotentials, such that the limiting mechanism becomes mass transport instead of electron kinetics. We therefore elucidate that the empirical exponential relationship between island density and nucleation pulse overpotential is not enough to draw conclusions on electrode kinetics, where additional validation of the growth process is essential.Beyond careful control of electrochemical parameters, here we show that neglecting the macroscopic surface characteristics of polycrystalline substrates can lead to major ambiguity in nucleation and growth dynamics of metal nanoparticles. We show here that XRD characterization prior to deposition is a simple additional measure to tailor metal nanoparticle electrochemical growth on ITO.

A Novel Junction Temperature Estimation Method Independent of Bond Wire Degradation for IGBT

The insulated-gate bipolar transistor (IGBT) junction temperature is crucial for condition monitoring, reliability assessment, and health management. However, the existing IGBT temperature monitoring methods are affected by the aging of IGBT bond wires. A novel junction temperature estimation method independent of bond wire degradation for IGBT is proposed in this paper. On-state voltage drop and turn-on gate voltage overshoot are analyzed for dependence on the junction temperature and bond wire degradation. These two temperature and bond wire monitoring electrical parameters are combined by the Artificial Neural Network (ANN), to eliminate the effect of bond wire degradation. A double pulse test platform is built to verify the influence of temperature and bond wire degradation on on-state voltage drop and turn-on gate voltage overshoot, which agrees with the theoretical analysis. Lots of experimental data at various collector-emitter voltages, load currents, IGBT junction temperature, and bond wire degradation are tested. A BP neural network is trained for junction temperature monitoring and its optimal number of hidden layers is studied. The experimental results show that the junction temperature estimation method based on the neural network can effectively eliminate the effect of bond wire degradation. The estimation error is around 4.219°C. The proposed method has the advantages of high accuracy and a wide application range for junction temperature monitoring.