Perfectly notched long-period fiber grating filter based on ICP dry etching technique

Abstract

This study presents a new process using inductively a coupled plasma dry etching method to manufacture a long-period fiber grating filter with exact period, vertical sidewalls, and smooth etched surfaces, and the filter is thus named a perfectly notched long-period fiber grating (NLPFG). This process can dramatically reduce production time, and thereby provide higher volume production. The fabricated NLPFG has periods of 640 μm, resonant-attenuation wavelengths of 1518 nm, and maximum resonance-attenuation of 21.79 dB. A force induced loss-tunable calibration of the NLPFG filter was implemented, and a monotonically increasing quadratic fitting was observed. The results demonstrated that the proposed NLPFG has a much better period precision compared to corrugated LPFG, and it has great potential for a loss-tunable filter and force transducer applications.

Rapid 3D Patterning of Poly(acrylic acid) Ionic Hydrogel for Miniature pH Sensors

“…PAA ionic hydrogel is then patterned into a series of periodical micropads on the surface of the microfiber. Since photopolymerization process causes shrinkage in polymer, PAA micropads will act as “hoops” and apply a periodic strain modulation on the microfiber . Thanks to the enhanced overlapping between the fundamental guided mode and cladding modes, such a periodic strain modulation will cause a resonant scattering phenomena in the microfiber, and induce a coupling from the fundamental guided mode to a specific cladding mode at the resonant wavelength.…”

Long-Period Fiber Grating Sensor Based on a Conductive Polymer Functional Layer

“…In 2012, Chiang et al [ 8 ] proposed an LPFG fabricated using inductively coupled ion etching. This primarily involved the use of photolithography to imprint a periodic structure on a photoresist to be imposed on an optical fiber.…”

A simple all-fiber comb filter based on the combined effect of multimode interference and Mach-Zehnder interferometer

“…Optical fiber comb filters, a key component with compact size and good compatibility with the fiber systems are widely used in the multiwavelength fiber lasers 1 and optical networks 2 to process the optical signals and isolate the neighboring channel signals and to reduce the cross-talk. A variety of techniques have been proposed to realize all-fiber comb filter function such as fiber Bragg grating filters 3 – 5 , Sagnac loop interferometers 6 – 8 , Fabry–Perot filters 9 – 11 , birefringent fiber filters 12 and Mach-Zehnder (M-Z) filters 13 – 16 . However, these techniques suffer from the disadvantages of high cost and complex fabrication.…”