A compact low-beat-frequency dual-polarization distributed Bragg reflector (DBR) fiber laser for high-frequency
ultrasound detection has been demonstrated. The laser was fabricated in high germanium concentration, small-core
erbium-doped fiber with very small birefringence. Induced birefringence to the fiber during the UV inscription process is
small (~10-7) because of the small fiber core (4.2-μm) and consequently the laser beats at a low frequency of ~20 MHz,
making frequency down-conversion unnecessary. The beat frequency can be adjusted by controlling the side-exposure
time of the UV light irradiating the gain cavity, providing a simple approach to multiplex a large number of DBR fiber
lasers of different frequencies in series using frequency division multiplexing (FDM) technique.
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.