Modified self-Kerr-nonlinearity in a four-levelN-type atomic system

Polarized dependence of nonlinear susceptibility in a single layer graphene system in infrared region

“…In another study, the enhanced cross-Kerr nonlinearity both theoretically and experimentally has been investigated in a four-level tripod atomic system [32]. The self Kerr nonlinearity of the two, three and fourlevel atomic system has been studied theoretically and experimentally by Sheng et al [33]. Recently, Hamedi and Juzeliūnas proposed a phase sensitive model for achieving giant Kerr nonlinearity in a closed-loop configuration [34].…”

“…In nonlinear optics, due to significant role of Kerr nonlinearity in some important phenomena [26,27], it is favoraitable to have giant Kerr nonlinearity in low light intensities [28]. Recently it has been shown that the giant enhanced Kerr nonlinearity in multi-level atomic systems with zero linear absorption can be possible by different mechanisms [29][30][31][32][33][34][35][36][37][38]. Niu et al investigated giant Kerr nonlinearity via double dark resonances in a four-level atomic system [35].…”

Electromagnetically induced transparency and nonlinear pulse propagation in a combined tripod and Λ atom-light coupling scheme

“…Consequently the five-level tripod and Λ scheme becomes equivalent to a conventional N -type atomic system [29,84] shown in figure 3. Since the quantum interference term β vanishes, equation (18) simplifies to…”

“…The absorption is suppressed due to a quantum mechanical interference between different excitation pathways of atomic energy levels leading to the EIT. The EIT has various important applications in quantum and nonlinear optics, such as slow and stored light [7][8][9][10][11][12], stationary light [13,14], multiwave mixing [15][16][17], optical solitons [18][19][20][21][22][23], optical bistability [24,25] and Kerr nonlinearity [26][27][28][29][30]. Using the slow light greatly enhances the light-matter interaction and enables nonlinear optical processes to achieve significant efficiency even at a singlephoton level [26,[31][32][33][34][35][36][37][38].…”

Uniform phase modulation via control of refractive index in a thermal atom vapor with vanishing diffraction or absorption

“…In order to achieve such phase shifts, there have been extensive studies by utilizing nonlinear effects enhanced by quantum coherences and interferences. For example, self- [6,7] or cross- [8][9][10][11] phase modulation based on Kerr effect have been proposed using electromagnetically induced transparency (EIT) [12][13][14][15], spontaneously generated coherences [16] or active Raman gain [17,18] media, not only in gaseous-phase such as atomic alkali atoms, but also in solid-state media including optical fibers [3,19,20], quantum wells [21,22], and superconducting qubits [23][24][25]. Several schemes have been experimentally tested in cold [2, 11,26] or thermal atomic systems [6,10,27,28], where small nonlinear phase shifts up to the order of one radian are achieved.…”