Effective Length Research Articles

Vertical directional coupling based grating emission engineering for optical phased arrays

In this Letter, a novel, to the best of our knowledge, vertical directional coupling waveguide grating (VDCWG) architecture is proposed to increase the length of waveguide grating antennas for large aperture on-chip optical phased arrays (OPAs). In this new architecture, the grating emission strength is engineered by the vertical directional coupler, which provides additional degrees of design freedom. Theoretical analysis and numerical simulation show that the VDCWG can adjust the grating strength in the range of more than two orders of magnitude, corresponding to an effective grating length more than a centimeter. For proof-of-concept, a VDCWG antenna with a length of 1.5 mm is experimentally demonstrated. The grating strength is measured to be 0.17 mm−1, and the far-field divergence angle is 0.061°. A 16-channel OPA is also developed based on the proposed VDCWG, which proves the potential of the new architecture for large aperture OPAs.

Thiopyran-Fused Polycyclic Aromatic Compounds Synthesized via Pt(II)-Catalyzed One-Pot Ring-Expansion and 6-endo Cyclization Reactions.

A series of thiopyran-fused polycyclic aromatic hydrocarbons (PAHs) have been straightforwardly synthesized from 2,5-di(1-en-3-ynyl)thiophene-containing precursors via one-pot ring-expansion and 6-endo cyclization reactions. The reaction monitoring and the density function theoretical calculation suggest that the ring-expansion reaction occurs prior to 6-endo cyclization. Moreover, the absorption profiles of the thiopyran-fused PAHs suggest that the π-conjugation extension on the side of the cyclopentadiene ring in the cyclopenta[b]thiochromene core is predominant in prolonging the effective conjugation length, while the effect from extension on the other side is negligible. Furthermore, all of the thiopyran-fused PAHs exhibit halochromic properties. Upon the addition of trifluoromethanesulfonic acid, fluorescence "off-on" switches can be found for these thiopyran-fused PAHs. Therefore, this work not only provides a new synthetic approach for one-pot ring-expansion and 6-endo cyclization reactions but also expands the diversity of thiopyran-fused PAHs.

Effect of pre-plasma on terahertz radiation from two-color laser plasma filaments in a collinear geometry

Terahertz (THz) radiation from air plasma in the presence of pre-plasma in a collinear geometry is investigated experimentally, where the pre-plasma is formed by a pre-pulse with a Gaussian beam profile and the measured THz radiation is driven by a main laser pulse. The pre-plasma has a de-focusing effect for the main pulse passing through it, which reduces the effective length of the plasma filament formed by the main laser pulse for THz radiation. It is found that only the part not overlapped by the pre-plasma can actually produce THz radiation. Thus, the amplitude of the THz pulse driven by the main pulse can be modified by changing the spatial separation between two plasma filaments. The experimental observations are qualitatively in agreement with our numerical simulation results. It is also found that the change of the time delay between the pre-pulse and the main pulse does not change the THz radiation amplitude for a given spatial separation. This study suggests a practical way for the manipulation of THz waves through an interaction between laser plasma filaments.

Black hole interior quantization: a minimal uncertainty approach

Abstract In a previous work we studied the interior of the Schwarzschild black hole implementing an effective minimal length, by applying a modification to the Poisson brackets of the theory. In this work we perform a proper quantization of such a system. Specifically, we quantize the interior of the Schwarzschild black hole in two ways: once by using the standard quantum theory, and once by following a minimal uncertainty approach. Then, we compare the obtained results from the two approaches. We show that, as expected, the wave function in the standard approach diverges in the region where classical singularity is located and the expectation value of the Kretschmann scalar also blows up on this state in that region. On the other hand, by following a minimal uncertainty quantization approach, we obtain 5 new and important results as follows. 1) All the interior states remain well-defined and square-integrable. 2) The expectation value of the Kretschmann scalar on the states remains finite over the whole interior region, particularly where used to be the classical singularity, therefore signaling the resolution of the black hole singularity. 3) A new quantum number is found which plays a crucial role in determining the convergence of the norm of states, as well as the convergence and finiteness of the expectation value of the Kretschmann scalar. 4) A minimum for the radius of the (2-spheres in the) black holes is found 5) By demanding square-integrability of states in the whole interior region, an exact relation between the Barbero-Immirzi parameter and the minimal uncertainty scale is found.

Calculation of Column Pile Heave in Deep Excavation Based on the Rebound–Recompression Method

Excessive column pile heave may result in engineering disasters such as instability of retaining structures and cracking of existing engineering piles in deep excavations. However, factors such as support weight, changeable support restraint resistance, and soil disturbance at the bottom of the excavation are often ignored or simplified in existing calculation methods but have a significant impact on the calculation results. Based on field soil parameters obtained by the rebound–recompression method, a semi-analytical method is proposed for estimating column pile heaves in a deep excavation. This method considers the influence of soil disturbance, the weight of the retaining structure, and the changeable horizontal support restraint, making the calculation result more consistent with the realistic situation. This method can also be used to analyze load transfer between the pile and the surrounding soil. The rationality of this proposed calculation method is verified by measured data, where the variation in pile stress state during deep excavation is analyzed. Finally, a parametric study is conducted, and the results show that the excavation size and the excavation depth have a great influence. However, the heave is hardly affected by the value of the limit relative displacement. The use of long piles with small diameter and the method of small block excavation are effective means to control the column pile heave. When the excavation area is large or the effective pile length is short, the factor of the position of the column pile cannot be ignored.

The role of nanosize dependence of dislocation and surface roughness concentrations to calculate lattice thermal conductivity in In0.53Ga0.47As nanofilms

ABSTRACT Systematic empirical relations were established for the nanosize-dependent surface roughness, ε ( D ) , dislocations, N D ( D ) , and effective length to examine their effects on the temperature-dependent lattice thermal conductivity (LTC) within the framework of the Morelli-Callaway model for In0.53Ga0.47As alloy films with thicknesses ranging from 10 to 70 and 1400 nm, the latter representing the material’s bulk state. The results were analyzed for film thicknesses of 2, 5, 200, and 500 nm, under the assumption that electrons and impurities are unaffected by nanosize, while a small alloy parameter significantly and sensitively alters the LTC curve in medium and high-temperature regions. According to these new findings, and considering phonon scattering processes, the LTC’s temperature dependence is sufficiently reduced at the nanoscale and fits well with the available reported experimental findings. It was also discovered that the LTC’s peak maximum value and its corresponding temperature are influenced by the film’s dislocation concentration, surface roughness, and thickness. Unravelling the complex interplay between nanosize-dependent dislocation and surface roughness concentrations becomes critical for a thorough knowledge when examining the delicate nuances of LTC in In0.53Ga0.47As nanofilms. Finally, the Morelli-Callaway-based model has been modified to calculate LTC for nanofilms without fitting parameters, provided their related bulk state values are known.

Hollow fiber membrane governed microjet flow regime for confined crystallization of large‐sized crystal aggregates

AbstractConfined crystallization can realize controllable nucleation and growth of crystals with targeted morphologies in a restricted region. Here, we achieved confined reactive crystallization within a novel micro columnar jet flow regime constructed by the hollow fiber membrane. The interface of the jet flow corresponds as the restricted region for reactive crystallization, and the large‐sized calcium carbonate (CaCO3) crystals aggregates with millimeter length can ordered and self‐assembly grow along the boundary of this region. Formation mechanism of the jet flow was systematically investigated by real‐time observation and force analysis. The detected detachment‐regrowth cycle during the experiments furtherly uncovered the potential for continuous operation. Linear (diameter: 0.12–0.3 mm; length: 1.5–3.1 mm) and lamellar crystals (thickness of 200–300 nm and average area of 0.21 mm2) were obtained by effectively manipulating the diameter and effective length of jet flow.

Thickness‐Dependent Formation Capacity and Mechanism of Planar (β)‐Conformation in Polydiarylfluorenes for Stable Deep‐Blue Polymer Light‐Emitting Diodes

AbstractConjugated polymers with p‐orbital overlap show intramolecular‐conformation‐dependent photophysical and electrical properties. Compared to the non‐planar segments, the planar conformation segments have a relatively long effective conjugated length and rigid backbone structure, which are beneficial for the enhancement of optoelectronic properties. Herein, the effect of film thickness on the formation capacity of planar (β) conformations in polyfluorene (poly[4‐(octyloxy)‐9,9‐diphenylfluorene‐2,7‐diyl]‐co‐[5‐(octyloxy)‐9,9‐diphenylfluorene‐2,7‐diyl], PODPF) for the fabrication of stable deep‐blue polymer light‐emitting diodes (PLEDs) is explored. Thickness‐tunable films with thicknesses ranging from 15 to 270 nm by controlling the concentration of precursor solution are prepared. The main observations are as follows. The PODPF chains in thin films are less likely to adopt the β conformations associated with the loose interchain packing in nano‐aggregates than those in thick films. Red‐shifted and well‐resolved emission spectra are observed for the annealed film with a high thickness, indicating the greater presence of β‐conformation segments. More interestingly, interchain aggregation is a necessary but not sufficient condition for the formation of β conformations. Finally, PLEDs based on β‐conformation segments have outstanding brightness, low turn‐on voltage, and stable deep‐blue electroluminescent behavior, confirming the unique advantage of planar conformation for optoelectronic applications.

Improving the stability of a planar tape-spring hyper-redundant manipulator

The planar tape-spring hyper-redundant manipulator presented in this paper is mainly constructed from tape springs, fixed-drive components, and mobile-drive components. It not only has high robustness and excellent transformability, but also high packaging efficiency. However, when the manipulator extends to a long range in motion experiments, some segments of the tape springs buckle. To address this drawback, a kinematic model of the planar tape-spring hyper-redundant manipulator is established, and, a configuration planning method based on a virtual spring model is proposed to solve the inverse kinematics problem. To enhance stability, the column stability is then incorporated into the configuration planning model. This approach relies on only configuration planning to prevent buckling. An alternative approach of adding auxiliary rods into the manipulator is also proposed. With this method, extra intermediate supports have been added to the manipulator. The effective column length of some segments is shortened, which effectively increases the critical buckling load of those segments of the tape spring. Finally, a prototype was subjected to motion and stability experiments to validate the presented approaches and analysis.

Gradient elasticity in Swift–Hohenberg and phase-field crystal models

The Swift–Hohenberg (SH) and phase-field crystal (PFC) models are minimal yet powerful approaches for studying phenomena such as pattern formation, collective order, and defects via smooth order parameters. They are based on a free-energy functional that inherently includes elasticity effects. This study addresses how gradient elasticity (GE), a theory that accounts for elasticity effects at microscopic scales by introducing additional characteristic lengths, is incorporated into SH and PFC models. After presenting the fundamentals of these theories and models, we first calculate the characteristic lengths for various lattice symmetries in an approximated setting. We then discuss numerical simulations of stress fields at dislocations and comparisons with analytic solutions within first and second strain-gradient elasticity. Effective GE characteristic lengths for the elastic fields induced by dislocations are found to depend on the free-energy parameters in the same manner as the phase correlation length, thus unveiling how they change with the quenching depth. The findings presented in this study enable a thorough discussion and analysis of small-scale elasticity effects in pattern formation and crystalline systems using SH and PFC models and, importantly, complete the elasticity analysis therein. Additionally, we provide a microscopic foundation for GE in the context of order-disorder phase transitions.

KTA-OPO for 1742 nm laser generation driven by a composite Nd:YVO4-based self-Raman laser

In this work, a double-end diffusion bonded Nd:YVO4 self-Raman laser was designed to drive an intracavity, noncritically-phase-matched KTiOAsO4 (KTA) optical parametric oscillator (OPO). Both conversion efficiency and output power at 1.7 µm (the wavelength of the OPO signal field) were improved by effectively reducing the thermal lens effect and increasing the effective length of self-Raman medium. At an incident pump power of 15.4 W, the output power for 1742 nm output laser reached 2.16 W with a conversion efficiency of 14%, and the output having a pulse width of 10.5 ns and a pulse repetition frequency of 90 kHz. The competition between the OPO and cascaded Raman laser was observed when the incident pump power was above 12.4 W. The results highlight that in order to improve output power at 1742 nm, it is critical that both the cascaded, second-Stokes field at 1313 nm and the signal field generated at 1534 nm from the 1064 nm field driving the KTA-OPO be minimized, if not completely suppressed. This laser system combining the processes of stimulated Raman scattering and optical parametric oscillation for the generation of laser emission at 1742 nm may find significant application across a broad range of fields including biological engineering, laser therapy, optical coherence tomography and for the generation of mid-infrared laser wavelengths.

Determination Of Drag And Inertia Coefficients By An Analytical Model

Hard structures like dykes or groins have been recognized for their negative environmental impact and limited durability in the face of climate change (Sutton-Grier et al., 2015). The concept of Shore Soft Engineering (SSE) has allowed ecological considerations to be embedded in the design of coastal protection (Hartig et al., 2011). Among emerging defense structures, nature-based solutions are built with natural materials and rely on physical properties and mechanisms observed in nature. They aim to protect, manage and restore ecosystems while providing some benefit to the human-being and biodiversity (Cohen-Shacham et al., 2016); they offer an interesting alternative to hard structures. However, implementing these solutions in urbanized coastal areas where ecosystems are vulnerable can be challenging. Another alternative approach is using biomimetic solutions, which can provide the functions of natural systems like seagrass, dunes, or coral through robust human-made constructions. Natural habitats exist in a variety of more or less complex forms, ranging from rigid (mangroves, coral) to flexible (seagrass) (Mullarney and Henderson, 2018); and they drive changes in the current profile, in wave dissipation or in sediment motion. Understanding how to mimic these systems, in particular their internal geometry and hydrodynamic effects, is challenging. This complexity makes the development of biomimetic solutions difficult (Perricone et al., 2023). In this context, this study strictly focuses on wave dissipation by flexible systems. Wave dissipation by natural habitats has been extensively studied through laboratory experiments (Houser et al., 2015) and in-situ measurements (Bradley and Houser, 2009). The pioneer analytical model (Dalrymple et al., 1984) depicted aquatic vegetation as rigid cylinders; however, the rigidity assumption fails to capture the inherent flexibility of plants. Alternative strategies emerged to account for this flexibility, such as using an empirical drag coefficient (Mendez and Losada, 2004) or introducing an effective length, representing the length that a rigid cylinder would have to dissipate the same wave height as flexible cylinders (Luhar and Nepf, 2016). However, to define this effective length or an empirical drag coefficient, it is necessary to carry out in-situ measurements. Numerous analytical models based on force balance (Luhar and Nepf, 2016; Leclercq and de Langre, 2018) have been developed to represent the movement of flexible vegetation like seagrass. These models depict the flexible vegetation as a series of segmented rigid stems attached to each other and subjected to oscillating flows. Some models attempt to link stem motion with wave dissipation to integrate this coupling into numerical models (Yin et al., 2022). However, these models still require unknown quantities such as drag and inertial coefficients. The present study aims to develop an analytical model for determining drag and inertial coefficients based solely on the geometry, the structure flexibility and wave forcing. At last, the method could help better represent the dissipation into numerical simulations without the need for prior parametrization.

The influence of viscous slab rheology on numerical models of subduction

Abstract. Numerical models of subduction commonly use diffusion and dislocation creep laws from laboratory deformation experiments to determine the rheology of the lithosphere. The specific implementation of these laws varies from study to study, and the impacts of this variation on model behavior have not been thoroughly explored. We run simplified 2D numerical models of free subduction in SULEC, with viscoplastic slabs following (1) a diffusion creep law, (2) a dislocation creep law, and (3) both simultaneously, as well as several variations of model 3 with reduced resistance to bending. We compare the results of these models to a model with a constant-viscosity slab to determine the impact of the implementation of different lithospheric flow laws on subduction dynamics. In creep-governed models, higher subduction velocity causes a longer effective slab length, increasing slab pull and asthenospheric drag, which, in turn, affect subduction velocity. Numerical and analogue models implementing constant-viscosity slabs lack this feedback but still capture morphological patterns observed in more complex models. Dislocation creep is the primary deformation mechanism throughout the subducting lithosphere in our models. However, both diffusion creep and dislocation creep predict very high viscosities in the cold core of the slab. At the trench, the effective viscosity is lowered by plastic failure, rendering effective slab thickness the primary control on bending resistance and subduction velocity. However, at depth, plastic failure is not active, and the viscosity cap is reached in significant portions of the slab. The resulting high slab stiffness causes the subducting plate to curl under itself at the mantle transition zone, affecting patterns in subduction velocity, slab dip, and trench migration over time. Peierls creep and localized grain size reduction likely limit the stress and viscosity in the cores of real slabs. Numerical models implementing only power-law creep and neglecting Peierls creep are likely to overestimate the stiffness of subducting lithosphere, which may impact model results in a variety of respects.

EFT corrections to scalar and vector quasinormal modes of rapidly rotating black holes

Quasinormal modes characterize the final stage of a black hole merger. In this regime, spacetime curvature is high, making these modes effective tools to probe potential corrections to general relativity. In this paper, we utilize the effective field theory framework to compute the leading-order correction to massless scalar and electromagnetic quasinormal modes. Proceeding perturbatively in the size of the effective field theory length scale, we describe a general method to compute the frequencies for Kerr black holes of any spin. In the electromagnetic case, we study both parity even and parity odd effective field theory corrections, and, surprisingly, prove that the two have the same spectrum. Furthermore, we find that, the corrected frequencies separate into two families, corresponding to the two polarizations of light. The corrections pertaining to each family are equal and opposite. Our results are validated through several consistency checks. Published by the American Physical Society 2024

Fracture performance of fiber reinforced geopolymer: Synergetic perspective

It is well-known the hybridization of different types of fibers exaggerates the contribution of mono fiber reinforcement on the mechanical and/or fresh properties of the concrete. Despite this fact, very few researchers have pointed out the synergetic effect of hybrid fibers on the fracture response of the geopolymer concretes. Hence, the present work seeks to extend the current knowledge of material science to cover the synergetic effect of hybrid fibers. To this end, a total of 15 mixtures, including plain matrix were manufactured. Steel, carbon, and glass fibers were incorporated into the mixtures at varying ratios. For the fracture evaluations, the rectangular prisms with the central notches were exposed to a three-point static bending test. Crack formations on the specimen surfaces were recorded through the 2D digital image correlation (DIC) method. Test results were examined in terms of some mechanical and fracture properties of geopolymer composites. Accordingly, the compressive strength, Young's modulus, flexural strength, limit of proportionality, and residual strengths were evaluated as the mechanical properties, while the fracture energy, characteristic length, effective crack length, initial stress intensity factor, and unstable stress intensity factor were considered as the fracture properties. Based on the experimental results, carbon fiber was found to be capable of increasing pre-peak mechanical response, while the steel and glass fibers were useful in improving the post-peak fracture properties of geopolymer concretes. In most cases, similar results were also attained for the hybrid fiber-reinforced concretes.

Monte Carlo simulation study on the reliability of concrete-filled HSS beam-column design provisions

Revisions were recently proposed to the way in which concrete-filled hollow structural section (HSS) members are handled in CSA S16. These revisions were based on previous research, comparisons to experiments, and a first-order reliability method analysis of existing provisions for compression and flexural members. In this paper, this topic is further expanded by using Monte Carlo Simulations (MCS) to determine the inherent reliability of the previous and new design rules for concrete-filled rectangular hollow section (RHS) and circular hollow section (CHS) beam-columns. A representative set of concrete-filled RHS and CHS members with variations in concrete strength, wall slenderness, effective length, and loading eccentricity are analyzed. Using MCS, the reliability index (β+) of each is determined over a range of live-to-dead load (L/D) ratios. Inherent β+ values are compared to the code-specified target (i.e., β+ = 3.0 per Annex B of CSA S16) and the CSA S16:19 and AISC 360-16 provisions.

Dry-out limit enhancement strategy in sodium heat pipes: Overfilling effect and modified capillary limit model

Despite the significant impact of the filling ratio on dry-out of heat pipe, current operating limit models do not adequately address this factor. This study proposes an advanced capillary limit model that incorporates the effect of the filling ratio. An experimental study was conducted to compare the operating limits of sodium heat pipes with filling ratios of 107 % and 246 %. The results showed that the existing capillary model is difficult to predict the operating limits based on filling ratios, leading to significant deviations between theoretical predictions and actual outcomes. Specifically, a heat pipe filled to 107 % experienced dry-out at a point 31.1 % lower than expected, while a heat pipe filled to 246 % reached dry-out at 20.2 % higher than expected. Notably, the overfilled heat pipe maintained a steady state even at 10.5 % above the expected dry out point. The key point of the proposed model, based on optical imaging and temperature data at dry-out, is that the excess liquid in vapor region travels and forms a liquid plug at the end of the condenser, which shortens the length required for capillary transport. Based on this insight, the Chi model was modified to predict the operating limit of overfilled heat pipes more accurately within a 5 % margin of error. The study highlights the critical role of filling ratio in heat pipe design, noting that overfilling can shorten the effective capillary length through liquid plug formation, thereby increasing the dry-out limit. However, these pools also limit the reach of sodium vapor and potentially reduce the effective area of the condenser.

Planar curved path following controller for a small fixed-wing unmanned aerial vehicle with constrained parameters optimized by nonlinear model predictive control

Path following presents a pivotal challenge within the realm of small fixed-wing unmanned aerial vehicles. Firstly, a Lyapunov-stable path guidance law was formulated to follow specific planar curved paths. To ensure differentiability of the guidance law, a modified, smooth saturation function was derived. Secondly, an analysis was conducted to ascertain the interrelationship between control parameters and input constraints, thereby identifying the relevant parameter domains. Thirdly, the nonlinear model predictive control technique was harnessed to optimize both guidance law parameters, enhancing the unmanned aerial vehicle’s capacity to achieve optimal performance in both straight-line and circular path following, hereafter referred to as PFC_NMPC. By leveraging Lyapunov stability arguments for switched systems, the stability of the corresponding nonlinear switched system was guaranteed. In this study, square and circular paths were generated to assess the path-following control of a simulated fixed-wing unmanned aerial vehicle. The performance of various guidance laws, including those with fixed parameters (PFC), those with parameters tuned using fuzzy logic (PFC_FL), PFC_NMPC, vector field, and pure pursuit with line-of-sight, was compared. Notably, the proposed PFC_NMPC method exhibited the ability to expedite the unmanned aerial vehicle’s convergence to the desired path while maximizing the effective flight path length.

Properties and interfacial performances with magnesium phosphate cement of coir fiber treated by an efficient water bath method: Effect of immersion temperatures and times

The pronounced brittleness and crack-prone nature of magnesium phosphate cement (MPC) can be efficiently addressed by coir fiber (CF). For coir fiber reinforced magnesium phosphate cement composite (CF-MPC), the ability of the fibers to fully exploit their mechanical properties is the key to enhancing the matrix's ability to bear the load, which in turn affects the interfacial bonding between CF and MPC. While the water bath treatment is superior to chemical treatment in improving the properties and the interfacial performances with MPC of CF, less research on the optimal treatment temperature and time has been conducted. In this study, the results of the fiber axial tensile test and monofilament pull-out test are used to determine the ideal water bath treatment settings. In order to better clarify the microscopic process, the structural alterations of the materials were further examined using Fourier transform infrared (FTIR) spectroscopy, Van Soest (VS), and scanning electron microscopy (SEM). The results suggested that, when the immersion temperature is 80°C and the immersion time is 120 minutes, the tensile strength of CF is even higher than that of polypropylene fibers, reaching the maximum value of 304.9 MPa. The interfacial bond-bearing capacity and interfacial damage energy of CF-MPC reached the highest values of 14.5 N and 117.4 N·mm at 100°C and 80°C for 120 minutes of immersion, respectively. Moreover, there was an effective embedment length of CF in MPC after water bath modification. In addition, the computational modeling of immersion temperatures, times and embedment length on the bond-bearing capacity of the CF-MPC interface was established with a good fit.

Impact of the recessed gate depth on the GaN metal-oxide-semiconductor high electron mobility transistor performances: New insights on mobility extraction

This paper provides a comprehensive study of the impact of the gate recess depth (RD) on the GaN-on-Si MOS-HEMTs DC performances. IDS = f(VGS) and IDS = f(VDS) measurements are conducted at 25 and 150 °C, respectively, in forward and blocking modes. The gate recessed depth (50, 150, and 350 nm) is modulated by adjusting the plasma etching time, which is a critical step for improving the dielectric/GaN interface quality and the gate channel electron mobility. Three distinct regions can be defined separately: the bottom, the sidewall, and the corner region being the junction between the two previous regions. To assess the impact of gate recessed depth (RD) on the several mobilities around the gate cavity first, we applied our previous methodology allowing us to extract the bottom (μbot) and the entire sidewall region mobility (μT), without distinction from the corner. The mobility of the transverse region was found surprisingly to increase with deeper RD. To gain insight into the impact of the RD on this transverse section, a new extraction methodology is proposed to extract separately the gate corner (μcorner) and sidewall (μSW) mobility. These extractions show that the corner mobility is found to be reduced compared to the sidewall one (μcorner < μSW) evidencing the different weighting contributions over the transverse mobility. Moreover, these mobilities are found to be more degraded compared to the bottom one, highlighting the different contributions on the on-state resistance (RON). Indeed, the on-state resistance is lowered with the shallower RD due to the reduced sidewall resistance contribution (lower sidewall length) and despite the incremental contribution of the bottom resistance (larger effective gate length). However, the shallower RD shows an increase in the drain–source leakage current in reason of a lower gate electrostatic control. Technology Computer Aided Design (TCAD) simulations of the three RD morphologies are carried out to validate the experimental trends and the proposed methodology.