In this study, we developed and fabricate an array of microstructured MIR fibers of silver halide crystals. Firstly, the modal analysis of photonic crystal fiber arrays was carried out by means of program packages, which are based on offsurface integral- and differential-equation formulations, and the optimal parameters for medical thermography application were chosen. Then, the fibers were fabricated using extrusion technique and seven fiber segments were assembled. Each individual fiber has a matrix with the diameter of 525 μm, six hexagonally arranged inserts with lower refractive index than matrix’s one, and a central insert with a larger refractive index than matrix’s one. It was measured, that its cross-talk between adjacent fibers doesn’t exceed 5%. It was experimentally confirmed that the fiber structure allows transmitting infrared radiation with the wavelengths of 9.2-9.4 μm in a single-mode regime, yielding up to 100 μm in the mode field diameter for each individual fiber in the array. These wavelengths correspond to a temperature range of the human body, therefore the arrays may transmit thermal images of human tissues, including internal organs. We expect that such arrays can improve medical thermography techniques in the future.

Date Published: 16 April 2019
PDF: 8 pages
Proc. SPIE 11029, Micro-structured and Specialty Optical Fibres VI, 110290T (16 April 2019); doi: 10.1117/12.2520325

Published in SPIE Proceedings Vol. 11029:
Micro-structured and Specialty Optical Fibres VI
Kyriacos Kalli; Alexis Mendez; Pavel Peterka, Editor(s)