Results 41 to 50 of about 905 (174)

Pump–probe model for the Kramers–Kronig relations in a laser [PDF]

Journal of Optics, 2010
In this paper, we study theoretically a pump-probe model for the Kramers-Kronig (KK) relations during laser operation. A laser gain medium at steady state becomes saturated and the lasing field experiences a flat gain equal to the cavity loss. A solution of the laser equations reveals that the lasing frequency experiences a dispersion that is linear ...
Yum, Honam, Shahriar, Selim M.
openaire   +2 more sources

Mode‐Resolved Phonon Dynamics Under Chemical Pressure in SnTe Thermoelectrics

Advanced Science, EarlyView.
Chemical pressure reshapes low‐energy optical phonons in SnTe, altering their dispersion and scattering with heat‐carrying acoustic modes. Positive and negative pressure states modify phonon frequencies and lifetimes in distinct ways, revealing how mode‐selective lattice perturbations regulate acoustic–optical interactions and suppress lattice thermal ...
Zhihao Li, Jianhong Hu, Panpan Peng, Peng Cao, Hui Zhang, Yujie Zong, Yanhui Wu, Hongchao Wang   +7 more
wiley   +1 more source

Relating the Hall conductivity to the many-body Chern number using Fermi’s Golden rule and Kramers–Kronig relations

Comptes Rendus. Physique
This work provides a surprisingly simple demonstration that the quantized Hall conductivity of correlated insulators is given by the many-body Chern number, a topological invariant defined in the space of twisted boundary conditions.
Goldman, Nathan, Ozawa, Tomoki
doaj   +1 more source

Space-resolved chemical information from infrared extinction spectra

Scientific Reports, 2023
A new method is presented for the extraction of the complex index of refraction from the extinction efficiency, $$Q_{ext} {({\tilde{\nu }})}$$ Q ext ( ν ~ ) , of homogeneous and layered dielectric spheres that simultaneously removes scattering effects ...
Yushmantha Ishan Kalpa de Silva Thuiya Hennadige, Proity Nayeeb Akbar, Reinhold Blümel   +2 more
doaj   +1 more source

pyFDRT: An open‐source Python tool for Fourier‐transform analysis of the distribution of relaxation times in electrochemical impedance spectra

Bulletin of the Korean Chemical Society, EarlyView.
pyFDRT is an open‐source tool that converts an impedance spectrum into a quantitative equivalent circuit. Its Fourier‐transform stage requires no discretization basis or regularization parameter, and the non‐negative refinement selects its own parameters, and an information criterion determines the relaxation process count.
Chung‐Yul Yoo, Jaeku Park, Jeongjin Kim   +2 more
wiley   +1 more source

Tuning Stability and Optoelectronic Properties of CsSnI3 Via Rare‐Earth Doping

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Sn‐based halide perovskites are promising optoelectronic materials but are limited by poor stability. Thus, rare‐earth elements (RE) doping in CsSnI3 addresses this limitation, significantly enhancing thermodynamic, mechanical, and chemical stability, while simultaneously tuning electronic characteristics and modulating optical responses in the ...
Haowei Wang, Feiyu Zhou, Zhuo Li, Yanghao Luo, Tongtong Li, Yilun Liu, Shengying Yue   +6 more
wiley   +1 more source

DFT and Machine Learning Analysis of Eco‐Friendly Formamidinium Tin Iodide Perovskite Solar Cells: Optimizing Charge Transport Layers Through SCAPS‐1D Simulations

Energy Science &Engineering, EarlyView.
Machine learning using Random Forest, GB, XGBoost, and LightGBM regression algorithms: SHAP plot for PCE. ABSTRACT Tin‐based solar cells are the eco‐friendly alternative to the toxic lead‐based cells that are currently in use. In this context, Formamidinium Tin Iodide (FASnI3) emerges as a promising candidate due to its superior performance, exhibiting
Rabeya Khan, Md Rasidul Islam, I.K. Gusral Ghosh Apurba, Md. Amimul Ihsan, Rahat Ul Nasib, Mohammad Arefin, Md Rifatul Islam, Abu Zahid, Hasnain A. Ziad, Jehan Y. Al‐Humaidi   +9 more
wiley   +1 more source

Development of ultrafast time-resolved dual-comb spectroscopy

APL Photonics, 2017
Ultrafast time-resolved dual-comb spectroscopy (TR-DCS) has been demonstrated, which enables direct observations of transient responses of complex optical spectra by combining dual-comb spectroscopy with the pump–probe
Akifumi Asahara, Kaoru Minoshima
doaj   +1 more source

Ensuring Data Integrity in AI-Driven Materials Science: Why F-Sum Rules and Kramers-Kronig Relations Matter [PDF]

Nanoscale and Advanced Materials
Artificial intelligence (AI) is revolutionizing materials science, enabling accelerated discovery and optimization of advanced materials. However, the reliability of AI-driven models critically depends on the integrity of the underlying data.
Seyed Hamed Aboutalebi
doaj   +1 more source

Theory of Supercritical Coupling and Generalized Bound States in the Continuum

Laser &Photonics Reviews, EarlyView.
We develop a general theory of supercritical coupling and generalized bound states in the continuum (gBICs), revealing how interference between radiative and absorptive channels enables quality factors beyond conventional material‐loss limits. The framework unifies non‐Hermitian mode coupling, causality‐driven reactive interactions, and interference ...
Sergio Balestrieri, Bruno Miranda, Silvia Romano, Gianluigi Zito   +3 more
wiley   +1 more source