Aragon photonics

Technology

 

The BOSA is based on an all-optical method without O/E conversion and electrical post-processing until the light reaches the photodiode. The incoming signal under test (SUT) interacts with the beam of a known local oscillator (a TLS, used as probe) in a perfectly known material medium.

 

Deterministic and calibrated non linear effects dominated by the Brillouin effect are the physical base for the generation of the scanning filtering element, whose purely optical interaction with the SUT is directly measured in the photodetector. The outstanding narrowness of this “filter” is the ground for the high resolution and also high dynamic range.

 

With this new method, the span range, dynamic and resolution are independent variables and all of them can be maximised simultaneously.

 

The intention of the researchers behind the BOSA is to erase any source of uncertainties, moving parts or electrical conversions in order to make the instrument reliable, lasting and fast.

 

 

Based on the same measurement technique, the BOSA PHASE measures not only the amplitude of the spectrum but also the relative phase between components of discrete spectrums.

The Fourier analysis justify that any periodic signal is composed by a sum of sinusoidal signals with different amplitude, frequency and phase.  The frequency of the constituent signal is a multiple of the periodic signal.

The phase measurement technique uses a double Brillouin tunable filter with a frequency separation equal to the fundamental frequency of the signal under test. When sweeping the filter over the signal under test pairs of component are filtered simultaneously and relative phase information between them can be derived.

The complex spectrum provides complete information about the signal. By applying the Inverse Fourier Transform (IFFT) temporal variations of the amplitude, phase and instant frequency can be obtained.

 

 

Scientific Publications

 

“Very High Resolution Optical Spectrometry by Stimulated Brillouin Scattering”, IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 17, NO. 4, APRIL 2005 (see abstract)

 

“Stimulated Brillouin scattering gain profile characterization by interaction between two narrow-linewidth optical sources”, 19 September 2005 / Vol. 13, No. 19 / OPTICS EXPRESS (see article)