KEYWORDS: Single mode fibers, Switching, Astronomical imaging, Light sources, Light, Tunable lasers, Signal to noise ratio, Chemical oxygen iodine lasers, Power meters, Fiber couplers
Conventional single mode fiber (SMF), due to its electromagnetic interference immunity, light weight, physical flexibility and broad bandwidth for data transmission, has been well employed in space, such as optical communication [1], structural health monitoring of spacecraft [2], and attitude determining applications, e.g. interferometric fiber optic gyroscope (IFOG).
Erbium doped fibers (EDFs) based devices are widely employed in space for optical communication [1], remote sensing [2], and navigation applications, e.g. interferometric fiber optic gyroscope (IFOG). However, the EDF suffers severely radiation induced attenuation (RIA) in radiation environments, e.g. space applications and nuclear reactors [3].
The dependence of radiation induced attenuation (RIA) on Al concentrations was investigated for
γ-irradiated EDFs doped with different Er, Al and Ge concentrations. The dependence of RIA on dose was
found well fitted by power law, and linear dependence of adjusted α on Al concentrations was verified. When
the Al concentration was as low as 0.11%, an unknown RIA band with absorption peak around 800 nm was
observed, which might be related to Erbium ions.
The performance of an FOG using a DPB SFS in a laboratory environment is reported, and compared with the one
using an SPB SFS. The result shows that the DPB SFS has a larger linewidth and a higher pump efficiency than the SPB
one. When measuring the earth rotation rate, the FOG using the DPB SFS has lower random noise and smaller bias drift
(0.019 deg/√h and 0.18 deg/h) than that using the SPB SFS (0.023 deg/√h and 0.47 deg/h). If a DPB SFS was applied in
the space, its output loss due to radiation damage could be smaller than an SPB one because a DPB SFS used a shorter
EDF so that the total radiation induced loss is reduced.
Two EDFs with different radiation sensitivities were used in the photo-annealing tests. We compared photo-annealing
efficiencies obtained by using 532 nm and 976 nm lasers. The 532 nm laser with 10 mW showed better efficiency than
976 nm laser with 290 mW in a ~30 cm EDF. The recovery rate was 5.6 seconds of the half-height recovery time. The
532 nm laser possibly excited the defects and provided some thermal energy so that the defects could be recovered. The
annealing efficiency from using the 976 nm laser was close to the one purely from thermal annealing at ~330 °C. For
practical tests, we also built two SPB SFSs and a bidirectional SFS and measured the output power loss dependence on
pump power. Under the dose rate of 129.2 krad/hr, the recovery rate of output power loss was 0.009 dB/min when a 2.8
m EDF#1 co-pumped by both the 532 nm and the 976 nm lasers.
Mean-wavelength stable superfluorescent fiber sources composed of three kinds of EDFs were irradiated by a 60Co
source up to 2000Gy to compare their mean-wavelength drifts and output power losses.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.