Терагерцовый сканирующий рефлектометр для визуализации строения полимерных конструкций в аддитивном производстве

Abstract

Представлены результаты разработки и практического применения в аддитивном производстве системы рефлектометрии объектов в терагерцовом диапазоне частот для анализа структуры. Для непрерывной генерации электромагнитного излучения применялась лампа обратной волны, в качестве детектора использовался акустооптический преобразователь (Ячейка Голея). Управление рефлектометром реализовано с персонального компьютера через модуль ввода-вывода L-card E154 и штатный цифро-аналоговый преобразователь спектрометра СТД-21. Тестирование системы произведено на частоте 874 ГГц на образце композиционной конструкции, изготовленной методом 3D-печати.

The results of the development and practical application of a quasioptical system for reflectometry of objects in the terahertz frequency range for analyzing the structure in additive manufacturing of objects are presented. A backward-wave oscillator is used for continuous generation of electromagnetic radiation; an acousto-optic converter (Golay cell) is applied as a detector. The reflectometer is controlled by personal computer through the L-card E154 input-output module and the standard digital-to-analog converter of the STD-21 spectrometer. The system is tested at the frequency of 874 GHz on the 3D-printed composite structure sample. Our paper is terahertz reflectometer with a source of continuous monochromatic electromagnetic radiation based on a backward wave oscillator is presented. The purpose of this work in creating a scanning THz reflectometer is considered to have been achieved. At the same time, the following tasks are solved: a quasi-optical scheme of the reflectometer is selected and assembled; the hardware part of the system (all mechanisms and components) is implemented; a program for controlling the radiation intensity registration system is adapted for this task; the test sample is manufactured using 3D printing technology, the THz reflectometer is tes-ted. The obtained practical results of registration of the two-dimensio-nal distribution of the reflection coefficient show that the use of THz radiation is promising for visualizing the structure of structures obtained by additive technology. Further development of the project is planned by changing the construction of the positioning mechanism, which will provide micrometric calibration of the sample holder relative to the diaphragm. The use of the quasioptical scheme of the two-beam interfe-rometer for recording the phase distribution and amplitude of reflected THz radiation will allow obtaining information about the spatial location of defects (inhomogeneities) of products obtained by additive technology.