Novel long-period fiber grating using periodically released residual stress of pure-silica core fiber

Abstract

ThFl (Tutorial) 8:30am Passive components for WDM networks Bruce Nyman, JDS Fitel, 15 Meridian Road, Eatontown, New Jersey 07728The development of the erbium-doped fiber amplifier has led to the rapid deployment of wavelength-division multiplexed (WDM) systems. Passive components are used throughout WDM networks. For example, a typical amplifier will contain an isolator, a pump and signal multiplexer, and optical taps. Complete WDM systems require wavelength combiners and demultiplexers. For a DWDM system the demultiplexer represents the state of the art in passive components.In this tutorial, we will discuss the passive components found in a typical WDM system. For each one, device requirements and technology options will be examined. While passive devices may be simple in function, there are many performance issues such as insertion loss, return loss, polarization dependent loss, polarization mode dispersion and chromatic dispersion. Also, all of these characteristics have temperature and wavelength dependencies. For simple components, fabrication techniques include fused fiber and dichroic filter based devices. For demultiplexers, fiber Bragg gratings and waveguide routers must also be considered. In addition, we will note current standards for measurements and reliability.Long-period fiber gratings (LPFGs) are promising components in optical fiber communications. The LPFG is usually fabricated by photo-refractive effect using a UV-laser' or by fiber deformation by local heating method^."^ In this report, we propose a new technique 0.5 -0.4 s = 0.3 v W V Y-$ 2 0.2 W -0 ._ W 0.1 > w m .--2 0.0 ______ before heating -after heating I 0.1%

3D Finite Element Model for Writing Long-Period Fiber Gratings by CO2 Laser Radiation

“…A LPFG can be produced mechanically [9], chemically (etching) [10], by photonic processes (ultra-violet irradiation) [11] or thermally, either by applying an electric arc discharge [12] or a mid-infrared radiation (MIR) laser source [13,14]. Within the family of thermal techniques, MIR from CO 2 lasers has guaranteed better predictability and repeatability [15].…”

Investigation of the mechanisms of formation of long-period gratings arc-induced in pure-silica-core fibres

“…In previous publications concerning the fabrication of LPFGs in pure silica-core fibres by using arc-discharges [2] and CO 2 laser radiation [1,6], the formation of gratings was attributed to stress relaxation. However, stress measurements performed inside arcinduced gratings have shown only a slight modulation of the core stress corresponding to an index change of less than 4.2 × 10 −5 , which is typically one order of magnitude lower than required [7].…”

“…Therefore, these fibres can be used for the fabrication of long-period fibre gratings (LPFGs) suitable for applications under ionizing radiation. Several techniques of inscription of gratings in pure silicacore fibres have been proposed, namely the ones based on CO 2 -laser radiation [1], arc-discharges [2], OH-flooding with subsequent excimer ArF-laser irradiation [3], or exposure to femtosecond laser pulses [4]. In 2005, it was demonstrated that doses of gamma radiation up to 0.5 MGy have a negligible effect on the spectra of arcinduced long-period fibre gratings and also on their temperature and strain sensitivities [5].…”

Stabilization of semiconductor lasers by fiber Bragg gratings

“…The gratings thus produced featured high thermal stability, retaining optical properties up to 500 °C. Exception of the photosensitivity effect using variety of the UV lights, LPFGs and FBGs can also be formed by means of focused CO 2 laser pulses [5] , electric arc [6] , residual stress relaxation [7] , periodic micro bends [8] , and ion implantation [9] .…”