scholarly journals Second Harmonic Generation in Lithiated Silicon Nanowires: Derivations and Computational Methods

Author(s):  
Donald Boone

This research will examine the computational methods to calculate the nonlinear optical process of second harmonic generation (SHG) that will be hypothesized to be present during lithium ion insertion into silicon nanowires. First it will be determined whether the medium in which SHG is conveyed is non-centrosymmetric or whether the medium is inversion symmetric where SHG as a part of the second-order nonlinear optical phenomenon does not exist. It will be demonstrated that the main interaction that determines SHG is multiphoton absorption on lithium ions. The quantum harmonic oscillator (QHO) is used as the background that generates coherent states for electrons and photons that transverse the length of the silicon nanowire. The matrix elements of the Hamiltonian which represents the energy of the system will be used to calculate the probability density of second-order nonlinear optical interactions which includes collectively SHG, sum-frequency generation (SFG) and difference-frequency generation (DFG). As a result it will be seen that at varies concentrations of lithium ions (Li+) within the crystallized silicon (c-Si) matrix the second-order nonlinear optical process has probabilities substantial enough to create second harmonic generation that could possibly be used for such applications as second harmonic imaging microscopy.

2021 ◽  
Vol 3 (6) ◽  
pp. 36-46
Author(s):  
Donald C. Boone

This research will examine the computational methods to calculate the nonlinear optical process of second harmonic generation (SHG) that will be hypothesized to be present during lithium ion insertion into silicon nanowires. First it will be determined whether the medium in which SHG is conveyed is non-centrosymmetric or whether the medium is inversion symmetric where SHG as a part of the second-order nonlinear optical phenomenon does not exist. It will be demonstrated that the main interaction that determines SHG is multiphoton absorption on lithium ions. The quantum harmonic oscillator (QHO) is used as the background that generates coherent states for electrons and photons that transverse the length of the silicon nanowire. The matrix elements of the Hamiltonian which represents the energy of the system will be used to calculate the probability density of second-order nonlinear optical interactions which includes collectively SHG, sum-frequency generation (SFG) and difference-frequency generation (DFG). As a result, it will be seen that at varies concentrations of lithium ions (Li+) within the crystallized silicon (c-Si) matrix the second-order nonlinear optical process has probabilities substantial enough to create second harmonic generation that could possibly be used for such applications as second harmonic imaging microscopy.


Author(s):  
Donald Boone

This research will examine the computational methods to calculate the nonlinear optical process of second harmonic generation (SHG) that will be hypothesized to be present during lithium ion insertion into silicon nanowires. First it will be determined whether the medium in which SHG is conveyed is non-centrosymmetric or whether the medium is inversion symmetric where SHG as a part of the second-order nonlinear optical phenomenon does not exist. It will be demonstrated that the main interaction that determines SHG is multiphoton absorption on lithium ions. The quantum harmonic oscillator (QHO) is used as the background that generates coherent states for electrons and photons that transverse the length of the silicon nanowire. The matrix elements of the Hamiltonian which represents the energy of the system will be used to calculate the probability density of second-order nonlinear optical interactions which includes collectively SHG, sum-frequency generation (SFG) and difference-frequency generation (DFG). As a result it will be seen that at varies concentrations of lithium ions (Li+) within the crystallized silicon (c-Si) matrix the second-order nonlinear optical process has probabilities substantial enough to create second harmonic generation that could possibly be used for such applications as second harmonic imaging microscopy.


2018 ◽  
Vol 27 (01) ◽  
pp. 1850003 ◽  
Author(s):  
Mohamadreza Soltani

Here, we propose a novel plasmonic structure, called asymmetric plasmonic nanocavity grating (APNCG), which is shown to dramatically enhance nonlinear optical process of second harmonic generation (SHG). The proposed structure consists of two different metals on both sides of lithium niobate and a thin layer of graphene. By using two different metals the nonlinear susceptibility of the waveguide would be increased noticeably causing to increase SHG. On the other hand, it consists of two identical gratings on one side. By two identical gratings, the pump beam is coupled to two opposing SPP waves, which interfere with each other and result in SPP standing wave in the region between the two gratings. The distance between two gratings will be optimized to reach the highest SHG. It will be shown that by optimizing the geometry of proposed structure and using different metals, field enhancement in APNCG waveguides can result in large enhancement of SHG.


2007 ◽  
Vol 17 (09) ◽  
pp. 3253-3257 ◽  
Author(s):  
I. ŚLIWA ◽  
P. SZLACHETKA ◽  
K. GRYGIEL

This letter proposes a procedure for generation and control of chaotic beats in a dynamical system that is initially in the periodic state. The dynamical system describes a simple nonlinear optical process — second-harmonic generation of light. The periodic states of the system are found to be in analytical forms. We also investigate some aspects of synchronization of chaotic beats in two systems, detuned in the pump fields.


1996 ◽  
Vol 05 (02) ◽  
pp. 189-204 ◽  
Author(s):  
S. HORINOUCHI ◽  
H. IMAI ◽  
H. YAMASAKI ◽  
K. FUKAO ◽  
G.J. ZHANG ◽  
...  

Phase-matched blue second harmonic generation was observed in a corona-poled Corning 7059 glass film waveguide. The induced quadratic optical nonlinearity was examined by second harmonic generation with a time dependent decay for multi-complex of SiO 2, BaO,B 2 O 3 and/or Al 2 O 3. Glass films with every possible combination of composition were fabricated and examined, The glass composition of SiO 2- BaO-B 2 O 3 and/or SiO 2- BaO-Al 2 O 3 was found to play effective roles in maintaining the induced second order nonlinearity for a longer period of time. This is supposed to be related to distributed traps which come from complex of the glass components.


1999 ◽  
Vol 579 ◽  
Author(s):  
Sergey N. Rashkeev ◽  
Walter R. L. Lambrecht

ABSTRACTWe present our implementation of the length-gauge formalism of Sipe and coworkers (Phys. Rev. B 48, 11705 (1993); ibid 52, 14636 (1995)) using the linearized muffin-tin orbital (LMTO) method and discuss its application to the calculation of second order response functions. The importance of gap corrections beyond LDA is discussed. As primary application, we discuss the second harmonic generation (SHG) coefficients of the SiC polytypes and of the chalcopyrites of both the II-IV-V2 and I-III-VI2 families. These examples illustrate the relation of the second order response function to the modification of the crystal structure and chemical substitutions.


2013 ◽  
Vol 12 (02) ◽  
pp. 1250118 ◽  
Author(s):  
JING WEI ◽  
JIN-YUN WANG ◽  
MIN-YI ZHANG ◽  
GUO-LIANG CHAI ◽  
CHEN-SHENG LIN ◽  
...  

The second harmonic generation (SHG) hyperpolarizabilities of phenylalanine and homopolypeptides are investigated by configuration interaction among singly excited configurations (CIS) technique combined with the sum-over-states (SOS) method. The geometries of peptides containing phenylalanine ( Phe )n(n = 1–8) are optimized by B3LYP/6-31g(d) method, and they form the special structures like β-sheet (a common protein secondary structure). It is found that the energy gaps of various peptides are reduced and the hyperpolarizabilities are increased with the peptide chains lengthened. We discuss the origin of the second-order nonlinear optical response in phenylalanine homopolypeptides and confirm that the π → π* transitions in the aromatic residue of phenylalanine make the most important contributions to the second-order polarizability. Our results strongly suggest that the hyperpolarizabilities are dominated from the propagation direction of peptide chains.


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