Efficient single-mode Brillouin fiber laser for low-noise optical carrier reduction of microwave signals

Abstract

We experimentally demonstrate efficient optical carrier reduction of microwave signals with a single-mode 1.5-microm wavelength Brillouin all-fiber ring laser. Because of the tunable optical coupling, the lasing threshold of the short-length (20-m) fiber cavity is lower than 5 mW, and high conversion efficiencies (up to 60%) are obtained at any pump power up to approximately 200 mW. Using the single-mode Stokes beam as a seed for the stimulated Brillouin scattering process allows up to 40-dB optical carrier depletion with almost no added noise for an optically carried microwave signal at 6 GHz. In addition, using this resonator, we provide evidence of generation of high-spectral-purity beatnotes.

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

“…5 as a function of P in for ␣ cpl ϭ 0.10 and ␣ f ϭ 0.12. Experiments were performed 13 with a cavity that had these values of losses and resulted in a measured threshold of ϳ4 mW. The corresponding measurements are represented by filled circles in Fig.…”

“…We have also demonstrated 13 that the single-frequency Brillouin laser can be used for generation of highly pure rf signals, through the beat note between two optical waves, in the range of the frequency offset ( B ϭ 11 GHz) of the pump-to-Stokes waves. Such a beat note could be used for rf local-oscillator generation and distribution for the receive mode of radar systems.…”

“…Such multimode behavior of the circulating Stokes wave can be detrimental for applications such as optical distribution of analog rf signals. 13 To generate a single-longitudinal-frequency Stokes wave with a low power threshold, it is possible to use a short fiber ring laser 14 that is simultaneously resonant for pump and Stokes waves (doubly resonant cavity). The ring is made resonant for the pump wave's frequency, thus drastically reducing the SBS threshold in the short optical fiber.…”

Enhancement of Brillouin Scattering Signal in Perfluorinated Graded-Index Polymer Optical Fibers

“…On the other hand, Brillouin scattering in optical fibers [6,7], one of the most significant nonlinear processes, has been extensively studied, and a great number of useful applications have been reported so far, such as optical amplification [7], lasing [7,8], optical comb generation [8], microwave signal processing [9], slow light generation [10], phase conjugation [11], tunable delay [12], optical storage [13], core alignment of butt-coupling [14], and strain/temperature sensing [15][16][17][18]. For the purpose of improving the performance of these applications, Brillouin scattering has been investigated not only in silica single-mode fibers (SMFs) but also in some specialty fibers.…”

Brillouin Scattering in Polymer Optical Fibers: Fundamental Properties and Potential Use in Sensors

“…On the other hand, Brillouin scattering in optical fibers [6,7], which is one of the most significant nonlinear processes, has been widely studied. It has been applied to a number of useful devices and systems, such as optical amplifiers [7], lasers [7,8], optical comb generators [8], microwave signal processors [9], slow light generators [10], phase conjugators [11], tunable delay lines [12], and strain/temperature sensors [13][14][15]. Up to now, Brillouin scattering has been studied not merely for silica fibers but for some specialty fibers including tellurite glass fibers [16,17], As 2 Se 3 chalcogenide fibers [18,19], bismuth-oxide highly-nonlinear fibers [20,21], and photonic crystal fibers [22,23].…”