Space applications require compact, light weight, low power, low noise, and highly reliable sensors for attitude determination, and fiber-optic gyro (FOG) is one of the most suitable instruments among many candidates. To develop a space-grade FOG and other fiber-based sensors, fiber light source and components with extremely high reliability and radiation-hardened characteristics are most wanted. To develop these key components for space applications, NSPO had been funding domestic vendors for a truly radiation-hardened Er-doped fiber light source, and had implemented and demonstrated a unique 532 nm shorter-wavelength photoannealing technique having a fast and total recovery of radiation-induced-attenuation (RIA) of Er-doped fiber from 900 nm to 1700 nm spectra range. The half-time recovery of a tested Erdoped fiber sample was 5.6 seconds after the exposure to a Gamma radiation with an accumulated total dosage of 129.2 Krad. New test results at various photo-annealing configurations and wavelengths by various contract vendors are covered in this paper. In addition, 80 µm single mode specialty fiber with a unique polymer coating was developed. The special GGP (Glass-Glass-Polymer) fiber consists of a glass core, a reduced glass cladding (80 µm), a P-coat (90 µm) and buffer coats to give a final diameter of 130 µm. A series of bending fatigue test were carried out. In those tests, various standard single-mode fibers, BendSafe fibers, and GGP fibers were bended in 3 mm diameter, and immersed in an 85 °C bath. On average, the customed GGP fibers outperform standard SM fibers by a factor of 1000 in fiber life. We also did γ-radiation test on the customed GGP fiber and revealed a RIA of less than 0.1 dB/Km/Krad which is suitable for low earth orbit applications with less than 30 Krad total dosage.
Developments of truly radiation-hardened fiber light sources, and highly reliable sensing modules for space-grade FOGs
2013
15 Seiten, Bilder, 17 Quellen
Conference paper
English
SOLUTIONS - Mechanics - Ultrasonically Induced Fountains and Fogs
Online Contents | 2002