All-In-Fiber Optofluidic Sensor Fabricated by Femtosecond Laser Assisted Chemical Etching
This paper reports the stress-induced birefringence generated in an optical fiber using femtosecond laser (fs) irradiations and the fabrication of in-fiber waveplates and polarizers. Optical birefringence was created in a single-mode fiber by introducing a series of symmetric cuboid stress rods on both sides of the fiber core and along the fiber axis using a femtosecond laser. The stress-induced birefringence was estimated to be 2.4x10-4 at the optical wavelength of 1550 nm. By controlling the length of the stress rods, waveplates of the desired retardance can be fabricated. The stress-induced birefringence was further explored to fabricate in-fiber polarizers based on the polarization-dependent long-period fiber grating (LPFG) structure. For the in-fiber polarizer based on low order mode LPFG, a polarization extinction ratio of more than 25 dB was observed at the wavelength of 1527.8 nm. A high order mode LPFG based in-fiber polarizer, with a broad bandwidth of 100 nm near 1550 nm, was investigated as well. The in-fiber polarization devices with low insertion loss may be useful in optical communications and fiber optic sensing applications.
L. Yuan et al., "All-In-Fiber Optofluidic Sensor Fabricated by Femtosecond Laser Assisted Chemical Etching," Optics Letters, vol. 39, no. 8, pp. 2358-2361, Optical Society of America, Apr 2014.
The definitive version is available at http://dx.doi.org/10.1364/OL.39.002358
Electrical and Computer Engineering
Mechanical and Aerospace Engineering
Keywords and Phrases
Birefringence; Diffraction gratings; Fabrication; Fibers; Irradiation; Optical communication; Optical fiber fabrication; Optical fibers; Optical instruments; Polarization; Single mode fibers; Ultrashort pulses; Fiber-optic sensing; In-fiber; Long period fiber grating; Optical birefringence; Polarization devices; Polarization extinction ratio; Stress induced birefringence; Waveplates; Optical fiber communication; Femtosecond laser irradiation; In-fiber polarizer; Stress-induced birefringence
International Standard Serial Number (ISSN)
Article - Journal
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