Annealing Effects on Optical Losses in 3D-Printed Silica Fiber

Annealing effects on optical losses in silica optical fiber drawn from 3D-printed preform were investigated. An irreversible reduction in loss was observed through multiple annealing cycles at a temperature
$T =$

800
°
C
. Changes in Raman spectroscopy confirm densification of the core as the stresses in glass relax with annealing. The temperature-dependent loss in the 3D printed fiber is consistent with modal field overlap at the core-cladding interface.