Terahertz Time Domain Transmission Characterization of Magnetic Nanoparticles for Frequency Selective Surface Application

<b>Terahertz Time Domain Transmission Characterization of Magnetic Nanoparticles for Frequency Selective Surface Application</b><br/><br/><b><u>Kousik Pradhan^1*</u></b>, Shobha Shukla², Shri Ganesh Prabhu³, Sumit Saxena²<br/><br/>¹Centre for Research in Nanotechnology and Science, Indian Institute of Technology Bombay, Mumbai, MH, India – 400076<br/>²Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, MH, India – 400076<br/>³Department of Condensed Matter Physics & Materials Science, Tata Institute of Fundamental Research, Mumbai, MH, India – 400005<br/><br/><br/>Corresponding author email: *[email protected]<br/><b>Abstract</b><br/><br/>Terahertz time-domain transmission spectroscopy (THz-TDS), is an effective method for characterizing materials and monitoring processes. Metals, semiconductors, 2D materials, and superconductors have all been tested with this technique, which does not require physical touch to obtain accurate results. Terahertz (THz) spectroscopy has developed as a method for investigating dielectric and transient photoconductive characteristics of materials over the past few decades. Since it can measure electrical resistance without touching the sample and has a temporal precision of a few picoseconds. Due to the low energy of THz radiation and the narrow pulse width, THz-TDS technology is non-destructive when used for extracting visual data from materials (picosecond range). This paper reveals optical parameters extraction methods by using THz transmission spectroscopy technology. In summation, materials with a low absorption of terahertz radiation can benefit from the adaptability of transmission methods, while materials with a high absorption capacity can take advantage of the advantages of reflection methods. To measure the magnetic material's optical properties like refractive index and absorption coefficient, we employ a transmission-type terahertz time domain spectroscopic instrument. The observations and analysis are performed in both the time domain and frequency domain, and we examine the transmission of terahertz radiation through magnetic nanoparticles at frequencies from 0.1 to 3 terahertz (THz). In the past few years, magnetic materials based on frequency selective surfaces (FSS) have become indispensable in the design of gigahertz (GHz) and terahertz (THz) millimeter-wave filters, polarizers, absorbers, EMI shielding, antenna reflectors, and radar applications.Here we also propose frequency selctive surface structure theoretically by using CST-MW studio software.<br/><br/><b>Keywords:</b> Magnetic material, THz, FSS, CST-MW<br/><br/><b>References :</b><br/><br/>Ji, Y., Fan, F., Xu, S., Yu, J. & Chang, S. Manipulation enhancement of terahertz liquid crystal phase shifter magnetically induced by ferromagnetic nanoparticles. <i>Nanoscale</i> <b>11</b>, 4933–4941 (2019).<br/>Fan, F., Zhong, C., Zhang, Z., Li, S. & Chang, S. Terahertz chiral sensing and magneto-optical enhancement for ferromagnetic nanofluids in the chiral metasurface. <i>Nanoscale Adv</i> <b>3</b>, 4790–4798 (2021).<br/>Hlaing, M. Z. <i>et al.</i> 3D Microstructured Frequency Selective Surface Based on Carbonized Polyimide Films for Terahertz Applications. <i>Adv Opt Mater</i> <b>10</b>, (2022).<br/><br/><br/>&lt;quillbot-extension-portal&gt;&lt;/quillbot-extension-portal&gt;