Layout design fiber optic proximity connector with Expanded Beam technology

Abstract

This article discusses the layout of a non-contact fiber optic connector for high-power laser radiation delivery systems in the field using Expanded Beam technology (Beam Expander). The technology being implemented, in contrast to contact technology, helps to reduce optical loss from contamination and displacement of the core of optical fibers. The diameter of the beam after passing through the lens becomes 15 times larger than the core of the optical fiber, thereby reducing losses from dust particles at the ends of the optical fibers, which, due to their size, can introduce significant losses. In such connectors, it is proposed to use ball lenses since they are convenient to install and relatively inexpensive. The connector itself is a design with ball lenses, the radiation on which is first converted into a parallel light beam of a larger diameter, and then focuses again on the end of the output fiber. A model was developed, thanks to which the locations of spherical lenses were calculated relative to each other and relative to optical fibers, at which losses would be minimal. The prototype of the connector was assembled from the following components: multimode optical fiber delivery, laser pump diode 975 nm, micromotors, ball lenses and optical power meter. K-8 glass and transparent aluminum oxide Al2O3, traditionally called sapphire in optics, were used as lens materials. The relationship between the transmittance of radiation and the diameter of ball lenses was investigated. Such a connector can be used in laser delivery systems, such as explosive squibs in the aerospace and mining industries.