Narrowband optical filter, with a variable transmission spectrum, using stimulated Brillouin scattering in optical fiber

Abstract

A novel shape-adjustable narrowband optical filter utilizing stimulated Brillouin scattering in an optical fiber is proposed and demonstrated. In this scheme, binary-phase-shift-keying modulation is applied to the pump wave to broaden and shape the Brillouin gain spectrum. By choosing an appropriate modulation data pattern, we realized a flat-top steep-cutoff optical bandpass filter with a 3-dB bandwidth of 1.5 GHz and a 10-dB bandwidth of 2 GHz is realized. In addition, a tunable optical notch filter is also realized by deamplification of the anti-Stokes wave.

Four-fold reduction in the speed of light at practical power levels using Brillouin scattering in a 2-m Bismuth-oxide fiber

“…This is even more the case if one considers deliberately broadening the linewidth of the Brillouin gain in order to accommodate a typical communications signal (e.g. as in [5,6]) as this requires yet higher power levels. The need for high pump powers could in principle be overcome by using longer fiber lengths.…”

High-efficiency single-frequency Brillouin fiber laser with a tunable coupling coefficient

“…However, too strong an optical component can saturate high-speed detectors. SBS has been demonstrated [8][9][10][11] to be an appropriate mechanism for selectively filtering the excess optical carrier. In particular, recent publications have shown that the single-frequency operation of an efficient Brillouin fiber laser permits as much as 40-dB depletion of the optical carrier 16 while the quality of the rf signal is maintained in terms of phase noise.…”

“…1 However, SBS can be used in several applications, such as Brillouin fiber lasers, [2][3][4] Brillouin optical amplifiers, 5,6 SBS fiber sensors, 7 and optical processing of radio-frequency (rf) signals. [8][9][10][11] In optical fibers, SBS (described in Ref. 12, pp.…”

Design and performance evaluation of narrowband rectangular optical filter based on stimulated Brillouin scattering in fiber

“…And the tunability makes it more flexible to meet different requirements. Several methods have been proposed to implement such filters, including specially designed fiber Bragg gratings (FBG) [1], Fabry-Perot etalons [2] and stimulated Brillouin scattering (SBS) [3][4][5][6]. Among all the above methods, SBS is considered as one of the most promising techniques.…”

“…The wavelength of the SBS-based filter can be tuned easily by changing the wavelength of the pump. The filter bandwidth and the shape can be also flexibly changed by controlling the pump spectrum using external phase modulation [3], direct current modulation [4] and cascaded phase and intensity modulation [5]. However, it is very difficult to control the pump spectrum precisely in the previous works; therefore, the exact flat top and steep edges as the properties of ideal rectangular filter are hardly achieved.…”