Showing papers by "E. J. Friebele published in 1989"
TL;DR: The asymmetric stress inherent in PM fibers has been shown to reduce the permanent induced loss, while the recovery of the radiation-induced attenuation was found to be enhanced in fibers with Ge-F-doped silica clads.
Abstract: The loss induced in polarization-maintaining (PM) fibers by low dose rate [<0.01 Gy/h, where 1 Gy = 100 rads(Si)] radiation exposure has been found to vary from <0.4 to ≈ 6 dB/km-10 Gy, depending on the wavelength of measurement and the fiber. Correlations have been established between low dose rate response and the “permanent” induced loss determined by fitting the recovery of the induced loss following high dose rate exposure to nth-order kinetics. Using this technique, both 0.85- and 1.3-μm PM fibers have been found which show virtually no permanent incremental loss and would therefore appear to be resistant to low dose rate radiation environments. The asymmetric stress inherent in PM fibers has been shown to reduce the permanent induced loss, while the recovery of the radiation-induced attenuation was found to be enhanced in fibers with Ge-F-doped silica clads.
33 citations
26 Apr 1989
TL;DR: In this article, the results of low dose rate (< 1 rad/hr) exposures of several different kinds of polarization-maintaining (PM) fibers were reported, and the relationship between stress and radiation sensitivity was investigated using otherwise identical fibers in which varying levels of both symmetric and asymmetric stress have been induced by grinding the preform to varying depths.
Abstract: This paper reports the results of low dose rate (< 1 rad/hr) exposures of several different kinds of polarization-maintaining (PM) fibers. In addition, the relationship between stress and radiation sensitivity has been investigated using otherwise identical fibers in which varying levels of both symmetric and asymmetric stress have been induced by grinding the preform to varying depths.
19 citations
06 Feb 1989
TL;DR: In this paper, an approximate dose rate for a fiber-optic gyro in the spacecraft interior is estimated to be 1 krad/yr, which depends on such factors as the spacecraft orbit, shielding by the skin and structure, and sunspot activity.
Abstract: One likely application for polarization-maintaining (PM) fiber is in fiber-optic gyroscopes onboard spacecraft. Severe performance degradation could occur if the PM fiber is sensitive to the space radiation environment, which depends on such factors as the spacecraft orbit, shielding by the skin and structure, and sunspot activity. An approximate dose rate for a fiber gyro in the spacecraft interior is ~1 krad/yr.
10 citations
26 Apr 1989
TL;DR: In this article, the authors derived an empirical model for predicting the radiation induced loss in matched-clad single-mode optical fibers using orthogonal matrix analysis (OMA) and derived the dependence of fallout radiation sensitivity on fabrication parameters.
Abstract: This paper reports progress in the derivation of an empirical model for predicting the radiation induced loss in matched clad single-mode optical fibers. We have drawn fibers from a set of MCVD preforms which were produced over a range of fabrication conditions intended to span the variations encountered in commercial MCVD fiber production. Conclusions regarding dependence of fallout radiation sensitivity on fabrication parameters were drawn from the data through orthogonal matrix analysis.
7 citations
26 Apr 1989
TL;DR: In this article, the effects of transient irradiation on optical fibers were investigated at various optical power levels up to 28 mW at -55 and 23 C to investigate the temperature dependence and possible photobleaching effects at short times.
Abstract: This paper addresses two effects of transient irradiation on optical fibers. The recovery of the induced attenuation was measured from 100 ns to 1 ms in several fibers, including two pure silica fibers and three fibers with doped silica cores. Measurements were performed at various optical power levels up to 28 mW at -55 and 23 C to investigate the temperature dependence and possible photobleaching effects at short times. We also report studies of the luminescence induced by the transient irradiation for the same group of fibers.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
5 citations
TL;DR: In this paper, the effect of varying single mode fiber fabrication factors such as core and clad dopant concentrations, deposition conditions, and draw parameters on the recovery of the nuclear radiation-induced attenuation at 1.3 μm has been studied.
Abstract: The effect of varying single mode fiber fabrication factors such as core and clad dopant concentrations, deposition conditions, and draw parameters on the recovery of the nuclear radiation-induced attenuation at 1.3 μm has been studied. Statistically significant correlations of core factors have been established with a 24 experimental design, and separate one-dimensional experiments revealed the effect of clad [Ge] and [F].
1 citations
TL;DR: In this article, the results of specific studies of this differential attenuation induced in a series of polarization-maintaining (PM) fibers by both steady state and transient irradiations were reported.
Abstract: Recent studies have indicated that the birefringent-inducing stress of polarization-maintaining (PM) fibers decreases the long term, permanent loss induced by ionizing radiation and that light polarized along the two orthogonal axes of PM fibers may be attenuated differently by exposure to irradiation sources. This paper reports the results of specific studies of this differential attenuation induced in a series of PM fibers by both steady state and transient irradiations. It has been found that the response to ionizing radiation depends on the materials properties of the fiber, i.e. the core and clad dopants and/or degree of stress, and that the magnitude of the differential attenuation is small relative to the total or one-axis incremental loss.
1 citations