Design, Fabrication, and Testing of a Vacuum Chamber for Terahertz Spectroscopy.

• Grant number: 25/01256-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: December 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Jonathas de Paula Siqueira
• Grantee: Felipe Fávaro Henriques Netto
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 22/03035-9 - Development of ultrashort pulse sources in the vacuum ultraviolet and terahertz for spectroscopy of advanced materials, AP.PNGP.PI

Abstract

Terahertz (THz) spectroscopy is an innovative technique with growing applications in science and technology, encompassing the characterization of semiconductor materials, quantum materials, and pharmaceutical compounds. However, the absorption of THz radiation by atmospheric water vapor poses a significant obstacle, particularly at frequencies above 1 THz, compromising the quality and accuracy of measurements.Our laboratory recently developed a time-domain spectroscopy system (THz-TDS) covering the 0.1 to 4 THz range, with plans to expand to 9 THz by 2025. Currently, an acrylic chamber with a nitrogen atmosphere is used to minimize water vapor absorption. Although useful, this method presents operational drawbacks, such as high nitrogen costs and prolonged purge times, limiting the system's efficiency.This project aims to design, fabricate, and test a dedicated vacuum chamber for THz spectroscopy that will completely eliminate water vapor interference, reduce operational costs, and optimize measurement preparation time. The methodology is divided into three main stages: design and planning, fabrication and assembly, and experimental validation. The project includes the development of a detailed CAD model, selection of materials suitable for the vacuum system, and integration with optical windows specific to THz radiation.With this solution, we expect to substantially improve the quality of the data obtained, reduce operational costs, and drive advancements in THz spectroscopy in our laboratory. (AU)