Fabrication of fiber optic long period gratings operating at the phase matching turning point using an ultraviolet laser

Abstract

It is known that optical fiber long period gratings (LPGs) exhibit their highest sensitivity to environmental perturbation when the period is such that the phase matching condition is satisfied at its turning point. The reproducible fabrication of LPGs with parameters satisfying this condition requires high resolution control over the properties of the grating. The performance of an LPG fabrication system based on the point-by-point UV exposure approach is analyzed in this paper, and the control of factors influencing reproducibility, including period, duty cycle, and the environment in which the device is fabricated, is explored.

Optical fibre long period grating gas sensor modified with metal organic framework thin films

“…LPG with grating period of 110.7 m and of length 40 mm, was fabricated in a point-by-point fashion in boron-germanium co-doped optical fibre (Fibercore PS750) with cut-off wavelength 670 nm, side-illuminating the optical fibre by the output from a frequency-quadrupled Nd:YAG laser, operating at 266 nm [25]. The transmission spectrum of the optical fibre was recorded by coupling the output from a tungsten-halogen lamp (Ocean Optics HL-2000) into the fibre, analysing the transmitted light using a fibre coupled CCD spectrometer (Ocean Optics HR4000), Fig.…”

Manufacturing and Spectral Features of Different Types of Long Period Fiber Gratings: Phase-Shifted, Turn-Around Point, Internally Tilted, and Pseudo-Random

“…LPFGs were manufactured on photosensitive optical fibers with the point-by-point technique using an excimer KrF laser. Without any purpose to show the application of the realized gratings and in addition to the previous literature on the field [30,31], the attention of this paper will be completely focused on how all the above- Here, the manufacturing and spectral features of different type of LPFGs, ranging from standard (see Figure 1), phase-shifted (see Figure 2a) and internally tilted (see Figure 2b) gratings up to pseudo-random gratings (see Figure 2c), are described and discussed in detail. An in-house procedure, as well as an ad-hoc developed setup allow the high-quality manufacturing of any type of LPFGs with a total customization by setting different parameters, such as the grating period, the number of grating planes, the number of laser shots for each plane, etc.…”

“…LPFGs were manufactured on photosensitive optical fibers with the point-by-point technique using an excimer KrF laser. Without any purpose to show the application of the realized gratings and in addition to the previous literature on the field [30,31], the attention of this paper will be completely focused on how all the above-mentioned manufacturing parameters strongly influence the spectral features of the grating in the transmission spectrum.…”

Fabrication of fiber optic long period gratings operating at the phase matching turning point using an amplitude mask

“…It has been shown that the phase matching condition for each cladding mode contains a turning point and that the LPG exhibits the highest sensitivity when phase matching turning point (PMTP) is accessed. This can be achieved by choosing an appropriate LPG period and coating thickness 7,8 .…”

“…The photoinduction can be done using UV 8 , infrared 12 and CO 2 laser 13 , or by ion implantation 14 . Each individual part of the grating can be fabricated point-by-point 8,13 or, in the case of UV irradiation, an extended section of the fibre can be exposed to the beam via an amplitude mask 15 , that imposes a spatial modulation to the intensity of the laser beam.…”