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Effect of scratches.
Source publication
The capacity of optical communications networks has increased rapidly in the past several years with the introduction of wavelength division multiplexing (WDM) technology, and optical power in the optical fiber link has risen accordingly. However, when optical power rises, system reliability suffers, with problems like damage to the fiber or optica...
Context in source publication
Context 1
... terms of scratches on connector endfaces, we evaluated three kinds of samples, (1) without scratches in the core area, the level of products on the market, (2) with scratches in the core area due to inadequate polishing condition, which did not adversely affect connection loss, and (3) with scratches caused by a 5-μm file, which adversely affect connection loss. Five samples of each were evaluated, with the results shown in Table 1. No changes in the endface state was observed for any of the samples, and in those samples with large scratches made by the 5-μm file, a temperature increase of more than 50°C was observed. ...
Citations
... Other features of optical fibers, their refractive index profile and core radius, influence the overall amount of allowed density power before one of the limitations of the PoF system such as fiber fuse appears. This is a phenomenon in which only the core of the optical fiber melts locally due to high optical power in the fiber and the damage is propagated toward the light source [13]. There is an extensive body of work on power limits in optical fibers; however, the magnitude of the damage threshold is yet to be strictly established. ...
This paper introduces the concept of power over fiber (PoF) and potential applications envisioned in radio access networks with optical fronthauling using different types of optical fibers. It is an open discussion on exploring PoF technology with current experiments integrating analog radio over fiber using 5G-NR signals in compliance with 3GPP, PoF, and monitoring techniques and general requirements in future deployments along with its potential to be part of the energy efficiency strategy in beyond 5G networks.
... Fiber-endface damage is the main problem related to high-power transmission in optical fiber. In this effect, part of the optical power is absorbed by irregularities at the glass/air interface, generating heat and leading to catastrophic damage [18,19]. The theoretical CW damage threshold for the glass/air interface is ~1 MW/cm 2 . ...
... Fiber-end-face damage is the main problem related to high-power transmission in optical fiber. In this effect, part of the optical power is absorbed by irregularities at the glass/air interface, generating heat and leading to catastrophic damage [18,19]. The theoretical CW damage threshold for the glass/air interface is~1 MW/cm 2 . ...
The use of optical fibers is increasing in modern aircraft because this helps solve challenges of size, weight, communication, and reliability in new generation aircraft. This study describes a video and power transmission system using optical fibers (PoF) for in-flight entertainment (IFE) system application. We present the benefits and the limitations of this application, and we perform two practical experiments to demonstrate their performance. We used off-the-shelf devices in the experiments, such as one 15-Watt semiconductor laser operating at 808 nm, GaAs photovoltaic converters, optical transmitters and receivers, and video monitors. The power and video signals were transmitted using two 50-m length multimode fibers. In addition, we proposed and tested two types of energy transformation units (ETUs), which are responsible for supplying electrical energy to the IFE video monitor and the optical fiber receiver.
... Single-mode fibers (SMFs) are sufficiently robust to operate with optical power levels in the order of several watts but, if some triggering factor is given (e.g., an excessive bending), the fiber fuse effect can be initiated in the core at some point, from which it will propagate towards the light source. According to [14], at 1467 nm, the power threshold of SMFs is approximately 1.5 W, so that it is safe operating below this level with respect to fiber fuse. In more recent works, however, SMFs-based systems have been demonstrated to support launching power levels higher than 1.5 W (e.g., in [15], the authors used a launching power of 2.24 W and, in [16], of 2.0 W). ...
Research achievements in hollow-core photonic crystal fibers technology allow ascertaining such fibers as outstanding platforms for delivering high-power laser beams. Indeed, the key property underlying the success of this family of optical fibers for high-power beam delivery is their capability of efficiently transmitting light through empty space with minimal interaction with the fiber microstructure. In this context, here we widen the framework of hollow-core fiber-based beam delivery applications by demonstrating their utilization as promising platforms for Power-over-Fiber systems. Thus, we report on the use of a tubular-lattice hollow-core fiber to deliver a watt-level continuous-wave laser beam onto a photovoltaic converter and activate a representative camera circuit. We believe that the experiments reported herein allow identifying hollow-core fibers as eligible candidates for next-generation Power-over-Fiber devices potentially able to lift the power restrictions of current solid-core fiber-based Power-over-Fiber systems.
... We reported that the propagation velocities of fiber fuse in a step-index SMF and TriSFs, which were theoretically estimated at λ 0 = 1.064 µm, were in fairly good agreement with the experimentally determined values [44,45]. Several experiments had also been carried out on the fiber fuse phenomenon in the DSFs at λ 0 = 1.064, 1.467, and 1.55 µm [46][47][48][49][50][51][52][53]. ...
Silica-based optical fibers are the most important transmission medium for long-distance and large-capacity optical communication systems. The most distinguished feature of optical fiber is its low loss characteristics. A single-mode optical fiber (SMF) exhibits a very low transmission loss (0.142 dB/km) at 1.55 µm. Together with such low loss characteristics, zero chromatic dispersion near 1.55 µm is required for high capacity signal transmission. The zero-dispersion wavelength of optical fibers can be shifted to the vicinity of 1.55 µm by the mutual cancellation of material dispersion and waveguide dispersion. Such fibers are called dispersion-shifted fibers (DSFs). The unsteady-state thermal conduction process in several DSFs was studied theoretically by the explicit finite-difference method using the thermochemical SiO x production model. The calculated threshold power and velocity of fiber fuse propagation in a step-index SMF were in fair agreement with the experimental values observed at 1.55 µm. It was found that the calculated threshold powers were proportional to the effective cross sectional areas of several DSFs and there is a linear relationship between the threshold powers and the mode-field diameters in the range of up to 2 W. These results were in fair agreement with the experimental results observed at 1.55 µm.
... The high-power SMA connector utilizes air-gap-ferrule technology that eliminates the materials near the fiber end face that absorbs energy (e.g., epoxy). This absorption can damage the connector end face [56]. ...
... The material of the outercoating layer of the optical fiber absorbs the signal lost to the cladding region. When a highpower optical signal is propagated in the fiber, the energy absorbed by the coating in the zone of curvature is high, generating a local increase in temperature in the coating [56]. ...
... Currently, the most accepted general explanation for the fiber-fuse effect relates to the ignition of this effect with the increase of fiber optic absorption at a point with a high-temperature value [56]. In turn, the increase in optical signal absorption is responsible for the catastrophic temperature increase in the fiber core, reaching values higher than the vaporization temperature of the silica. ...
... Optical connectors for SMFs were developed for this purpose. Several research institutes have studied the high-power performance of single-mode fiber-optic connectors [22][23][24][25]. ...
... The high-power damage phenomenon in fiber-optic connectors was previously investigated from the viewpoint of the adhesion of absorbing organic materials, such as carbonblack-doped resin [22,25] and a thin layer of carbon black [24], on the core end faces in the connectors. Carbon black was used to represent organic contaminants in these studies. ...
... Samples contaminated with 5 wt% carbon-black-doped acrylate resin exhibited end face damage at an initial laser power 0 of 49 mW when they were exposed to CW laser light with a wavelength 0 of 1.55 m [22]. Seo et al. reported that optical connectors with lightabsorbing contaminants such as carbon black-doped epoxy resin and/or oil-based black ink showed end face damage at 0 = 2 W when exposed to laser light with 0 = 1.48 m [25]. ...
The evolution of both the core melting and fiber fuse phenomena in a single-mode fiber-optic connector was studied theoretically. Carbon black was chosen as a light-absorbent material. A thin absorbent layer with a thickness of 1
μ
m order was assumed to be formed between the fiber end faces in the connector. When a high-power laser operating at 1.48 or 1.55
μ
m was input into the connector, the temperature on the fiber core surface increased owing to heat conduction from the light-absorbent material. The heat flow process of the core, which caused the core to melt or the fiber fuse phenomenon, was theoretically calculated with the explicit finite-difference method. The results indicated that initial attenuation of less than 0.5 dB was desirable to prevent core fusion in the connectors when the input 1.48
μ
m laser power was 1 W. It was found that a core temperature of more than 4000 K was necessary to generate and maintain a fiber fuse.
... fibre fuse) [3] and damage to the fibre coating and optical components (e.g. end-faces of connectors) as well as danger to human eyes [3,4]. Mainly for short-haul or long-haul terrestrial links, an OPMo may be a useful and feasible way to measure and display the optical power along the network at many discrete places without the interruption of datacom or telecom services. ...
We describe a simple and inexpensive inline optical power monitor (OPMo) for polymer optical fibre (POF) links that are transmitting visible light carriers. The OPMo is non-invasive in the sense that it does not tap any guided light from the fibre core; rather, it collects and detects the spontaneous side-scattered light. Indeed, the OPMo indicates whether a POF transmission link has dark or live status and measures the average optical power level of the propagating signals without disconnecting the fibre link. This paper demonstrates the proof-of-principle of the device for one wavelength at a time, selected from a set of previously calibrated wavelength channels which have been found in the 45 dB dynamic range, with 50 dBm sensitivity or insensitivity by the use or non-use of a mode scrambler. Our findings are very promising milestones for further OPMo development towards the marketplace.
... where n 0 (= 1.46) is the characteristic refractive index of the core layer, P is the incident power of the light reflecting from the cavity wall, which is estimated by Eq. (24). ω 0 (∼ 4.5 µm) is the spot size radius of the laser beam when optical power in the optical fiber was assumed to take on Gaussian distribution, ∂n/∂T (= 1.23 × 10 −5 K −1 [5]) is the thermal coefficient of refractive index for silica glass, and l is the length of the heating core, where α exhibits large value. ...
We investigated the unsteady thermal conduction status in a single-mode optical fiber by numerical computation in order to visualize the mode of fiber fuse propagation. We assumed that the vitreous silica optical fiber underwent pyrolysis at elevated temperatures to form SiOx (x< 2). We also proposed a model in which the optical absorption coefficient of the core layer increased with increasing molar concentration of SiOx. By using the model, we calculated the temperature distribution in the fiber with the explicit finite-difference method. It was found that when a short core with 40 um length was heated to 2,923 K and a 2 W laser light (wavelength of 1.064 um) entered the core layer of an SMF-28 optical fiber, a thermal wave, i.e., a fiber fuse, with a peak temperature of about 34,000 K was generated at the boundary of the heating region near the light source. The fiber fuse was enlarged and propagated toward the light source at a rate of about 0.54 m/s. The calculated propagation velocity of the fiber fuse was in agreement with the experimental value. Moreover, the average temperature of the radiated region of the core layer was less than 7,000 K at a time of 4 ms after the generation of the fiber fuse and gradually approached a temperature of about 5,700 K. The final average temperature was close to the experimentally reported values.
We evaluated the threshold power of fiber fuse propagation in hole-assisted fibers (HAFs) using the finite-difference method and the model proposed by Takara et al.
... The limitation concerning the uses of SMF is because of low efficiency of the photovoltaic converters for 1300 to 1600 nm window and by the power limitation transmission for SMF. While a multimode fiber with 105 µm core can transmit at maximum optical power of 4.5 W in 830-nm, single mode fibers with 9-µm core can transmit at maximum 1.2 W in order to avoid destructive effects, such as, fiber fuse [4]. Despite the fact that more than one fiber can be used in general to transmit energy this approach is not used generally and rarely the sensors need just some few milliwatts to work [5]. ...
This work describes a non-continuous sensor operating technique in order to achieve a long reach sensing system, using power over fiber (PoF) in single mode fiber (SMF). Due to the use of super-capacitors and logical circuits in the sensor unit, the energy provided by PoF can be stored and used in an appropriated time. We demonstrated this approach with a micro video camera sensor powered by a 4.4-km SMF link in laboratory and by a 1.6-km link using optical ground wire cable (OPWG), installed between an electrical power substation and a tower of 138-kV overhead transmission line (OTL).
... It may burn the cable and cause fire in the cable. Experiments have shown that the bending diameter must be more than 20 mm at 1 W and more than 30 mm at 3 W [8]. ...
... It results in bright white visible light, propagating from the initiation point toward the laser source over more than 1.5 km in certain cases. The fiber fuse melts and vaporizes the core, and creates a periodical void structure [8]. The SMF-28 threshold power is equal to 1.4 W at the initiation point [8]. ...
... The fiber fuse melts and vaporizes the core, and creates a periodical void structure [8]. The SMF-28 threshold power is equal to 1.4 W at the initiation point [8]. Solutions exist in order to suppress fiber fuse propagation: hole-assisted fiber (HAF) and photonic crystal fiber (PCF) [9]. ...
We describe a quasi-all-optical extension dedicated to simplifying the deployment of submarine cabled observatories. Based on power-over-fiber technologies, high power supply and data are both transmitted in one optical fiber of a few kilometers in length. We study the Raman amplification on the down- and up-stream data in the static regime with the high optical power varying from 100 mW to 4 W over a 10 km long single-mode optical fiber. We focus on the data optical budget and signal to noise ratio dependence with respect to the high optical power value and the data optical wavelength. We also present the transmission quality in the dynamic regime of this quasi-all-optical extension.