Temperature Dependence of Transmission Loss of Chalcogenide Glass Fibers

Abstract

The temperature dependence of transmission loss for IR-transmitting chalcogenide glass fibers of sulfur (S)-based, selenium (Se)-based and tellurium (Te)-containing glasses were investigated above room temperature. The influence of temperature on transmission loss significantly depended upon the kind of chalcogen element in the glass. The losses of S-based and Se-based glass fibers were slightly sensitive to temperature. On the other hand, the loss of Te-containing glass fibers increased considerably with temperature. The higher the Te content was, the greater the temperature dependence of transmission loss became. The characteristic behavior of Te-containing glass fibers could be attributed mainly to the additional absorption of due to the increase in the number of thermally excited free carriers with Te content, analogous to Ge and GaAs semiconductors.

Infrared fibers

“…Considerable efforts by several Japanese corporations and agencies laid the groundwork for future developments in ChG fibers, including the Nippon Telegraph and Telephone Public Corporation (NTT) [157,323,324], Hitachi, Ltd. [325][326][327][328][329], Horiba, Ltd. [330], Non-oxide Glass R&D Co., Ltd. [331], the Kyota Semiconductor Corporation [332], the HOYA Corporation [333], Uniquely, ChGs cover the broadest IR spectrum of all IR glasses, have the highest optical linear and nonlinear refractive indices, and offer the widest tuning range of optical parameters achieved through compositional engineering. ChG fibers may potentially cover the entire span of QCL wavelengths.…”

Chalcogenide glass fibers: Optical window tailoring and suitability for bio-chemical sensing

“…5 indicates that sulfide and selenide glass fibers may be inadequate for many far-infrared applications. In this case, glasses containing tellurium are required to achieve wide IR transparency [23,[29][30][31][32][33][34]. One of the main challenges for the fabrication of long wave infrared fibers is to obtain a glass with a high tellurium content which does not crystallize during the fiber drawing process [34] and does not exhibit high charge carrier losses [23].…”

Effect of temperature on the absorption loss of chalcogenide glass fibers

“…The mechanism of multiphonon absorption for the telluride fiber is the same as that of the sulfide fiber discussed above. Inagawa et al 16 have shown that for the Ge-As-Se-Te glass system the activation energies for the multiphonon and free-carrier absorption are 0.06 eV ͑23-67°C͒ and 0.01 eV ͑77-127°C͒, respectively. Figure 8 shows that for the telluride fiber at T Յ 60°C the increase in loss beyond 9 m is mainly due to multiphonon absorption.…”

“…For the sulfide and the telluride fibers, d͑␣ RS ͒͞dT is determined and listed in Table 3 16 T g ϭ 473 K ͑sulfide͒, 538 K ͑tellu-ride͒, and dn͞dT ϭ 1 ϫ 10 Ϫ5 K Ϫ1 ͑sulfide͒, 9 ϫ 10 Ϫ5 K Ϫ1 ͑telluride͒. 16 At T ϭ 70°C for a 5-m-long sulfide fiber between 1 and 5 m the change in loss due to Rayleigh scattering, d␣ RS , is calculated to be less than 3.0 ϫ 10 Ϫ8 dB. Similarly at T ϭ 60°C for a 5-m-long telluride fiber, between 5 and 9 m, d␣ RS is calculated to be less than 2 ϫ 10 Ϫ9 dB.…”