We report the experimental observation of self-induced modulation instability (MI) in a Brillouin fiber laser made with a solid-core photonic crystal fiber (PCF) with strong anomalous dispersion. We identify this MI as the result of parametric amplification of optical sidebands generated by guided acoustic modes within the core of the PCF. It is further shown that MI leads to passive harmonic mode locking and to the generation of a picosecond pulse train at a repetition rate of 1.15 GHz which matches the acoustic frequency of the fundamental acoustic mode of the PCF. (C) 2013 Optical Society of America
Distributed Brillouin Fiber Sensor With Enhanced Sensitivity Based on
Anti-Stokes Single-Sideband Suppressed-Carrier Modulation
Minh Duc Nguyen,
Birgit Stiller,
Min Won Lee,
Jean-Charles Beugnot,
Herve Maillotte,
Alexandre Mottet,
Jerome Hauden,
Thibaut Sylvestre
We demonstrate an alternative technique to reduce pump depletion and to<br> improve sensitivity in the long-range Brillouin optical time-domain<br> analysis (BOTDA) sensor. Our BOTDA system uses an anti-Stokes<br> single-sideband suppressed-carrier modulation technique that balances<br> the pump depletion due to fiber loss. With this technique, we show both<br> numerically and experimentally a great improvement compared to the dual<br> sideband standard technique.
Long-range and high-resolution distributed Brillouin fiber sensors
T. Sylvestre,
M. W. Lee,
D. M. Nguyen,
Birgit Stiller,
J.-C. Beugnot,
H. Maillotte,
J. Hauden,
L. Thévenaz
Brillouin-based distributed optical fiber sensors have been the subject of intense research in recent years because they offer a unique solution for continuous, real-time monitoring in civil engineering and petroleum industry. These sensors provide strain or temperature measurements with meter spatial resolution over several tens of kilometers. In this work we demonstrate two new Brillouin fiber sensors with enhanced performances based on advanced modulation formats from high-speed lightwave communications systems. We first report a Brillouin distributed sensor with enhanced centimeter resolution using a digital phase-shift keying technique. The second one uses a quadrature phase-shift keying modulator as a single-sideband modulator to balance the pump depletion and the fiber loss by the Brillouin gain. Combined with a specially-designed in-line bidirectional Erbium-doped fiber amplifier, we demonstrate that this technique allows for the achievement of long-range distributed sensing over 100 km.
Contact
Research Group Birgit Stiller
Max Planck Institute for the Science of Light Staudtstr. 2 91058 Erlangen, Germany
