Gamma irradiation effects in optical fibres, splitters, and connectors

Abstract

The paper presents a brief overview of contemporary ELION techniques with stress on their use for material modification and dozimetry. In the attempt to avoid some common misjudges of irradiation effects, special attention is paid to exact definition of irradiation geometry and careful adjustment of dose rates, which en able a proper elaboration of experimental results. In particular, effects of γ -rays irradiation on properties of commercial optical fibres, splitters, connectors, and fibre joints are examined, which enables monitoring of irradiation effects in complex configurations made of materials with different radiation hardness (resistance). It has been established that γ -rays irradiation of the investigated elements influences, in different ways, the transmission of laser beam signals of various wavelengths, under different modulation regimes. After irradiation, the signal attenuation is noticeably larger, both in optical connectors and optical splitter, than be fore it, and the effect in creases in time. The effects are more pronounced at the 99 % than at the 1 % Y-splitter out put at both measured wave lengths, and are more pronounced at 1310 nm than at 1550 nm.

Rad predstavlja kratak osvrt na elionske tehnike sa akcentom na njihovoj upotrebi za modifikaciju materijala i dozimetriju. U pokušaju da se izbegnu neka uobičajena, pogrešna mišljenja o efektima zračenja, posebna pažnja je posvećena tačnoj definiciji geometrije zračenja i pažljivom prilagođavanju jačine doze, koji omogućavaju pravilnu obradu eksperimentalnih rezultata. Posebno su ispitivani efekti ozračivanja gama zracima komercijalnih optičkih vlakana, optičkih račvi, konektora i spojeva fibera, što omogućuje praćenje efekta ozračivanja na kompleksne konfiguracije uređaja od materijala sa različitom radijacionom otpornošću. Nađeno je da ozračivanje ispitivanih elemenata gama zracima na razne načine utiče na transmisiju signala – laserskih snopova različitih talasnih dužina i pod raznim efektima modulacije. Posle ozračivanja, slabljenje signala je znatno veće i kod optičkih konektora i kod optičke račve, nego pre njega, a efekat raste sa vremenom. Efekti su mnogo izraženiji kod 99 %, nego kod 1 % izlaza Y račve na obe merene talasne dužine, i više su izraženi na 1310 nm, nego na 1550 nm.