講演情報
[21a-P01-2]Nonlinear Optical Response of Jahn-Teller Susceptible Mixed Transition Metal Oxide
〇(D)Ankit Sharma1, Mansi Pathak2, C S Rout2, K V Adarsh1 (1.IISER Bhopal India, 2.Jain University, Bangalore, India)
キーワード：
Mixed transition metal oxides、Nonlinear optical response、High and low spin state
The sustainability of optical nonlinearities of material systems is crucial for future technological and fundamental importance e.g., optical switching, signal processing, SHG, photovolyaic, optical limiting, etc. In the last four decades, extensive works had been dedicated to advances in the nonlinear optics field but unable to replace the existing. However, 2D TMDCs, inorganic and organic perovskites showed considerable enhancement but they are limited due to their low growth yield, and high instability. Here, we have chosen mixed transition metal oxides MnCo2O4 and demonstrated its nonlinear optical response. Mostly, oxides are known wide bandgap materials and transparent for the visible and infrared regime. But the oxides from mixed transition metals with partially filled d-orbital provide an additional degree of freedom to exploit their oxides in the visible regime. Partial d-orbital of transition metals with tetrahedral/octahedral goes through structural distortion and stabilized the system energetically by splitting the conduction band into low and high-spin states. We exploit these properties and observed two optically active bands in optical absorption spectroscopy at ~ 768 nm and ~ 507 nm. Further, we investigated its third-order susceptibility by incorporating the open (OA) and close (CA) aperture standard Z-scan technique. We used 7 ns, 532 nm Gaussian shape laser excitation at 53 MW/cm2 and observed the valley at a tight focusing position with two shoulder peaks near the focus which is evidence of excited state absorption. Interestingly, the CA transmittance profile revealed the Kerr lensing effect i.e., self-focusing properties of MnCo2O4 under similar excitation. Finally, our study proposed another material system that can be a potential candidate for optics and photonics applications and therefore needs to be investigated extensively for the fundamental understanding of these emerging materials.