Enhanced photosensitivity in germanosilicate fibres exposed to CO<sub>2</sub> laser radiation
We report a novel method to increase the UV photosensitivity of GeO<sub>2</sub>:SiO<sub>2</sub> optical fibers based on exposure to CO<sub>2</sub> laser irradiation before grating writing. Fibers treated with a CO<sub>2</sub> laser can produce gratings...
Main Authors: | , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
1999.
|
Subjects: | |
Online Access: | Get fulltext |
Summary: | We report a novel method to increase the UV photosensitivity of GeO<sub>2</sub>:SiO<sub>2</sub> optical fibers based on exposure to CO<sub>2</sub> laser irradiation before grating writing. Fibers treated with a CO<sub>2</sub> laser can produce gratings with refractive-index modulation two times greater and a Bragg wavelength that can be 2 nm longer than those of untreated fibers. Experiments on GeO<sub>2</sub>:SiO<sub>2</sub> preform samples treated with a CO<sub>2</sub> laser in a way similar to the fibers showed a marked increase of the 242 nm absorption band, which is associated with an increase of germanium oxygen-deficient centers and is believed to be responsible for the higher photorefractive response. |
---|