Open AccessInline fiber optic power sensor featuring a variable tap ratio based on a tightly focused femtosecond laser inscription
Author(s) -
Peng Ji,
SeonU. Baek,
Chang-Hyun Park,
SangShin Lee,
Young-Eun Im,
Younghee Choi
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.014972
Subject(s) - optics , materials science , cladding (metalworking) , femtosecond , laser , optical fiber , photodiode , optical power , fiber laser , optoelectronics , wavelength , physics , metallurgy
We propose and demonstrate an inline fiber optic power sensor (IFPS) resorting to an embedded waveguide tap, which is formed to traverse across the cladding and core of a standard single-mode fiber. The tap was produced via a single-step inscription based on the femtosecond laser direct-writing method. A tightly focused pulsed laser beam has been particularly exploited to suppress the elongation along the laser propagation direction, thereby improving the cross-sectional symmetry of the created tap waveguide. The fabricated fiber optic tap has been stably combined with a photodiode via a compact package. The achieved tap ratio could be tuned from 1.0% to 5.9% at the wavelength of 1550 nm by adjusting the applied laser power, while the induced excess loss was kept below 0.6 dB. The proposed IFPS will be highly suitable for real-time power monitoring in a variety of applications, including optical communication networks and systems.