http://hdl.handle.net/2289/147 Wed, 11 Mar 2026 09:11:46 GMT 2026-03-11T09:11:46Z http://hdl.handle.net/2289/8684 Title: LIBS of BaSrTiO3 compounds using ANN based on a stationary state plasma model Authors: Amogh, M S; Xavier, Sebin Sebastian; Jose, Jeena Rose; Philip, Reji; Biju, P R Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is widely used for rapid material characterization and quantitative analysis due to its versatility and speed. Linking LIBS spectra to precise quantitative measurements is challenging because of nonlinear effects arising from surface variations, matrix interactions, and self-absorption. As a result, precise quantitative analysis has been a persistent challenge for the LIBS community. We perform stoichiometric evaluation of BaSrTiO₃ (BST) samples with varying compositions using a stationary-state plasma approach. BST is notable for its high dielectric performance and is employed in applications such as non-volatile memories, pyroelectric sensors, and electro-optic devices. We simulate the LIBS spectra using a two-zone plasma model under Local Thermodynamic Equilibrium (LTE) and fit them to experimental spectra to extract stoichiometry, electron density, and plasma temperature. A Controlled Random Search (CRS) algorithm is used to optimize the fit to find the stoichiometry accurately. Further, an Artificial Neural Network (ANN) is trained exclusively on synthetic spectra representing the constituent elements, and when applied to experimental spectra, it accurately predicts the stoichiometry of samples not seen during training. To our knowledge, this work is the first to employ a two-zone stationary-state plasma model to generate synthetic training data for an ANN, which is then successfully applied to predict elemental compositions from experimental spectra. Our findings show that a simple ANN based on one-dimensional plasma modelling enables rapid in-situ classification and stoichiometric analysis, reducing reliance on large experimental spectral datasets for machine learning. This approach could simplify the complexities associated with experimental spectral requirements for training and predicting elemental concentration using ML models. Description: Restricted Access. Wed, 01 Apr 2026 00:00:00 GMT http://hdl.handle.net/2289/8684 2026-04-01T00:00:00Z http://hdl.handle.net/2289/8681 Title: Quantum technologies with Rydberg atoms Authors: Barik, Shovan Kanti; Thakur, Aishwarya; Jindal, Yashica; Silpa, B S; Roy, Sanjukta Abstract: Rydberg atoms have highly controllable exotic properties such as strong inter-atomic interaction, high polarizability, and long lifetimes which enabled unprecedented progress in Rydberg atom-based quantum Technologies. We present a brief review of recent progress in the development of quantum technologies using Rydberg atoms. We highlight the recent advances in the various regimes of quantum technologies such as quantum Information processing, quantum sensing, quantum simulation of many-body physics and single-photon sources for quantum communications. Description: Open Access Fri, 12 Jul 2024 00:00:00 GMT http://hdl.handle.net/2289/8681 2024-07-12T00:00:00Z http://hdl.handle.net/2289/8680 Title: Gain, amplification, and lasing in a driven atom-cavity system Authors: Bahuleyan, Arun; Thakar, V R; Gokul, V I; Dinesh, S P; Venkatesh, B Prasanna; Rangwala, S A Abstract: Cold atoms coupled to an optical cavity provide an ideal platform for creating lasers without conventional population inversion. Such lasers can generate very high spectral purity, and the output can be precisely controlled by varying the atom-drive or atom-cavity parameters. In this letter, we report experimental observation of gain, amplification, and self-lasing within a continuously operated 85Rb magneto-optic trap (MOT), in the collective strong coupling regime of the atom-cavity system. The presence of MOT cooling lasers significantly alters the transmission properties of the cavity, and gain is observed in one of the vacuum Rabi peaks. The system makes a transition from an amplifying medium to a self-sustained laser as the MOT parameters are tuned. The underlying lasing mechanism is shown to be Mollow gain in the driven atomic ensemble, and is confirmed through the free-space absorption spectroscopy of the MOT. The free space gain required for the lasing action is significantly smaller in our system as compared to the cases where there is no collective strong coupling. Description: Open Access Tue, 15 Apr 2025 00:00:00 GMT http://hdl.handle.net/2289/8680 2025-04-15T00:00:00Z http://hdl.handle.net/2289/8679 Title: Cavity-based nondestructive detection of photoassociation in a dark magneto-optical trap Authors: Gokul, V I; Bahuleyan, Arun; Dinesh, S P; Thakar, V R; Rangwala, S A Abstract: The photoassociation (PA) of a rubidium dimer in a dark magneto-optical trap (MOT) is studied using atom-cavity collective strong coupling. This allows nondestructive detection of the molecule formation process as well as rapid and repeated interrogation of the atom-molecule system. The vacuum Rabi splitting (VRS) measurements from the bright MOT are carefully calibrated against equivalent measurements with fluorescence. Further loading rates in the dark MOT are determined using VRS. This method provides a reliable, fast, and nondestructive detection scheme for detecting the PA using the free atoms coupled to a cavity when the atoms are in a nonfluorescing state. Description: Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations) Thu, 16 May 2024 00:00:00 GMT http://hdl.handle.net/2289/8679 2024-05-16T00:00:00Z