Quantum theory of microcavity-modified fluorescence decay rate under a strong coupling condition

2000 ◽  
Vol 61 (3) ◽  
Author(s):  
Ying Wu
2021 ◽  
Author(s):  
Akhila Kadyan ◽  
Anil Shaji ◽  
Jino George

In this letter, we investigated the modification of oscillator strength of an asymmetric stretching band of CS<sub>2</sub> by strong coupling to an infrared cavity photon. This is achieved by placing liquid CS<sub>2</sub> in a Fabry-Perot resonator and tune the cavity mode position to match with the molecular vibrational transition. Ultra-strong coupling improves the self-interaction of transition dipoles of asymmetric stretching band of CS<sub>2</sub> that resulted in an increase of its own oscillator strength. We experimentally proved this by taking the area ratio of asymmetric stretching and combination band by selectively coupling the former one. A non-linear increase in the oscillator strength of the asymmetric stretching band is observed upon varying the coupling strength. This is explained by a quantum mechanical model that predicts quadratic behavior under ultra-strong coupling condition. These findings will set up a new paradigm for understanding chemical reaction modification by vacuum field coupling.


2021 ◽  
Author(s):  
Abbas Hamouleh-Alipour ◽  
Ali Mir ◽  
Ali Farmani

Abstract Bolometer sensors are prominent and excellent choice in technology because they do not need cooling. The trade-off between high sensitivity, fast response time, and strong light absorption is a key important challenge in bolometer sensors. Here, the bolometric effect for a high resistance sensitivity plasmonic sensing of total and profile infusion of radiation is studied for the proposed bolometer sensor based on plasmonic multilayer structure at 26° C. In the present study, by generating strong coupling condition between incident wave and surface plasmon polaritons (SPPs), a very narrow absorption spectra with high figure of merit (FoM) is achieved. The analytical model and numerical simulation are fulfilled based on the transfer matrix method (TMM) and 3-D finite-difference time-domain (FDTD), respectively. The narrow absorption spectra that generate by strong coupling with SPPs heats the silver thin film that leads to variation in temperature and supports TE surface mode. This temperature change rectifies the resistance of the metal thin film by the bolometric effect. So, optical characteristics of the proposed metasurface bolometer sensor, including quality factor (Q), sensitivity, and figure of merit (FoM) are calculated that Max sensitivity, FoM, and Q are 17.2 RIU-1, 530 and 434.5, respectively. Finally, we analytically simulate the temperature coefficient of resistance (TCR) in terms of wavelength and refractive index of analyte (na) that this resistance change can be monitored by an external electric model. The proposed plasmonic multilayer configuration is a very compact footprint structure that achieved high resistance sensitivity and FoM in comparison with any previous reports. This proposed thermal, optical, and electric plasmonic metasurface bolometer sensor can be used in different applications such as biophysics, biology, and environmental science.


1998 ◽  
Vol 70 (7) ◽  
pp. 1444-1451 ◽  
Author(s):  
Alan Van Orden ◽  
Nicholas P. Machara ◽  
Peter M. Goodwin ◽  
Richard A. Keller

2020 ◽  
Vol 102 (4) ◽  
Author(s):  
Carlo Forestiere ◽  
Giovanni Miano ◽  
Mariano Pascale ◽  
Roberto Tricarico

1988 ◽  
Vol 9 (1-3) ◽  
pp. 47-62 ◽  
Author(s):  
Kenneth M. Beck ◽  
Robert J. Gordon

The method of time-resolved optoacoustics was used to measure the rate of vibrational relaxation of CH3Cl(ν6) and CH3Br(ν6) by Ar. The pressure pulses generated by the relaxing gas revealed that the rate of production of translational energy from ν6 = 1 is approximately twice the decay rate of IR fluorescence from ν3 = 1. No evidence was found for a previously proposed bottleneck in rotational relaxation, which would have resulted in an acoustic relaxation rate slower than the fluorescence decay. The faster rates observed here can be explained qualitatively by a rapid energy release from energy levels above ν3 which precedes the IR fluorescence. A simple three-level model, however, is unable to explain our observations quantitatively.


2017 ◽  
Vol 15 (04) ◽  
pp. 1750027
Author(s):  
W.-J. Wu ◽  
K. Yan ◽  
Y.-Q. Xie ◽  
Yinzhong Wu ◽  
Xiang Hao

We put forward a measure for evaluating quantum speed limit for arbitrary mixed states of open systems by means of trace distance. Compared with some present measures, it can provide an optimal bound to the speed of the evolution. The dynamical crossover from no speedup region to speedup region happens during the spontaneous decay of an atom. The evolution is characteristic of the alternating behavior between quantum acceleration and deceleration in the strong coupling case. Under the condition of detuning, the evolution can be initially accelerated and then decelerated to a normal process either in the weak or strong coupling regime. In accordance with the uncertainty relation, we demonstrate that the potential capacity for quantum speedup evolution is closely related to the energy feedback from the reservoir to the system. The negative decay rate for the evolution results in the speedup process where the photons previously emitted by the atom are reabsorbed at a later time. The values of the spontaneous decay rate become positive after a long enough time, which results in the evolution with no speedup potential.


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