Publications by Kwang-Yong Song

High Spatial and Spectral Resolution Long-Range Sensing Using Brillouin Echoes

Luc Thévenaz, Stella Foaleng Mafang, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

While classical configurations have a practical spatial resolution of 1 meter, novel approaches have been demonstrated that can overcome this limit to offer spatial resolutions in the centimetre range, while preserving full measurand accuracy. ...

Optical Society of America2011

Recent progress towards centimetric spatial resolution in distributed fibre sensing

Luc Thévenaz, Stella Foaleng Mafang, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

Optical fibre sensors based on stimulated Brillouin scattering have now clearly demonstrated their excellent capability for long-range distributed strain and temperature measurements. The fibre is used as sensing element and a value for temperature and/or ...

The International Society for Optical Engineering2010

Time-Domain Distributed Fiber Sensor With 1 cm Spatial Resolution Based on Brillouin Dynamic Grating

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

We demonstrate an optical time-domain distributed fiber sensor showing the highest spatial resolution ever reported based on Brillouin dynamic grating in a polarization-maintaining fiber. In our scheme, the acoustic gratings containing the information on t ...

IEEE Institute of Electrical and Electronics Engineers2010

True Time Reversal through Dynamic Brillouin Gratings in Polarization Maintaining Fibers

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

A novel technique to realize true time reversal of an optical signal, using dynamic Brillouin gratings in high-birefringence fibers, is proposed. A data sequence of optical pulses with 2-ns duration was efficiently time-reversed. A numerical simulation of ...

2010

True Time Reversal via Dynamic Brillouin Gratings in Polarization Maintaining Fibers

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

A novel technique to realize true time reversal of an optical signal, using dynamic Brillouin gratings in high-birefringence fibers, is proposed. A data sequence of optical pulses with 2-ns duration was efficiently time-reversed. ...

Optical Society of America2010

Ultra Wide Range Tunable Delay Line Using Dynamic Grating Reflectors in Optical Fibers

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

We experimentally demonstrate a novel technique to realize a tunable delay line based on dynamic Brillouin gratings in a high birefringence fiber. A 8ns pulse signal is continuously delayed up to 184ns with minor distortion. ...

Optical Society of America2010

Advanced Brillouin-based distributed optical fibre sensors with sub-meter scale spatial resolution

Luc Thévenaz, Stella Foaleng Mafang, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

Classical configurations of Brillouin distributed optical fibre sensors show a spatial resolution limited by the phonon lifetime to 1 meter. Novel approaches can substantially overcome this limit through the prior activation of the acoustic wave. ...

IEEE2010

Time-domain distributed sensor with 1 cm spatial resolution based on Brillouin dynamic gratings

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin, Nikolay Primerov

We propose and experimentally demonstrate the highest-resolution BOTDA system ever reported using Brillouin dynamic grating in a polarization-maintaining fiber (PMF). Acoustic waves containing the information of local Brillouin frequency are generated by a ...

SPIE2009

Flexible Slow and Fast Light in Optical Fibers

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin

A method to achieve an extremely wide and flexible control of the group velocity in an optical fiber using stimulated Brillouin scattering is presented. Group velocities below 71,000 km/s on one hand, well exceeding the speed of light in vacuum on the othe ...

IEEE2006

La lumière lente et rapide: une future pièce maîtresse pour la photonique

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin

Nous présentons une technique permettant de réaliser un contrôle extensif et très souple de la vitesse de groupe de signaux se propageant dans une fibre optique. Ce contrôle, directement piloté par une source lumineuse, est effectué par le truchement de ga ...

2006

Highly Efficient Slow and Fast Light Generation via Brillouin Scattering in As2Se3 Chalcogenide Fiber

Luc Thévenaz, Kwang-Yong Song

Delaying and advancement of optical pulses using stimulated Brillouin scattering in As2Se3 fiber is demonstrated. Pulses can be delayed by 37 ns in a 5-m-long fiber with a pump power as low as 60 mW. ...

Optical Society of America2006

Highly efficient Brillouin slow and fast light using As2Se 3 chalcogenide fiber

Luc Thévenaz, Kwang-Yong Song

We demonstrate the generation of slow and fast light based on stimulated Brillouin scattering in As2Se3 chalcogenide fiber with the best efficiency ever reported. The Brillouin gain of 43 dB is achieved with only 60-mW pump power in a 5-m single-mode chalc ...

2006

Time biasing due to the slow-light effect in distributed fiber-optic Brillouin sensors

Luc Thévenaz, Kwang-Yong Song

The influence of the slow-light effect on the performance of distributed Brillouin sensors is studied. We show that, while in most situations it can be neglected, it may greatly affect the results obtained for certain experimental configurations. More spec ...

Optical Society of America2006

Flexible Slow and Fast Light Using Tailored Brillouin Spectra in Optical Fibers

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin

Stimulated Brillouin scattering makes possible the generation of synthesized gain spectra, so that innovative slow light schemes can be realized, ranging from broadband tunable delays to a zero-gain situation identical to an ideal electromagnetically-induc ...

OSA2006

Arbitrary-bandwidth Brillouin slow light in optical fibers

Luc Thévenaz, Kwang-Yong Song

Brillouin slow light in optical fibers is a promising technique for the development of all-optical buffers to be used in optical routers. The main drawback of this technique up to now has been its narrow bandwidth, normally restricted to 35 MHz in conventi ...

2006

Broad-bandwidth Brillouin slow light in optical fibers

Luc Thévenaz, Kwang-Yong Song

We experimentally demonstrate that Brillouin slow light with an arbitrary large bandwidth can be readily obtained in conventional optical fibers using a simple and inexpensive pump spectral broadening technique ...

IEEE2006

Progress in Brillouin Slow Light and Its Impact in Fiber Sensing

Luc Thévenaz, Kwang-Yong Song, Sang Hoon Chin

This paper reviews the major advances in Brillouin slow light devices along the last two years. We also focus on the positive and negative implications of this effect in the development of fiber sensors. ...

Optical Society of America2006

Observation of pulse delaying and advancement in optical fibers using stimulated Brillouin scattering

Luc Thévenaz, Kwang-Yong Song

We demonstrate experimentally that it is possible to control optically the group velocity of an optical pulse as it travels along an optical fiber. To achieve this control we use the effect of Stimulated Brillouin Scattering. In our experiments we have ach ...

2005

Optically controlled slow and fast light in optical fibers using stimulated Brillouin scattering

Luc Thévenaz, Kwang-Yong Song

We demonstrate a method to achieve an extremely wide and flexible external control of the group velocity of signals as they propagate along an optical fiber. This control is achieved by means of the gain and loss mechanisms of stimulated Brillouin scatteri ...

AIP American Institute of Physics2005

Mapping of chromatic-dispersion distribution along optical fibers with 20-m spatial resolution

Luc Thévenaz, Kwang-Yong Song

The accurate mapping of chromatic-dispersion distribution along single-mode optical fibers with the best spatial resolution ever reported is experimentally demonstrated. The method consists of a new way of probing four-wave-mixing (FWM) efficiency along th ...

IEEE Institute of Electrical and Electronics Engineers2005