Rayleigh scattering-assisted narrow linewidth Brillouin lasing in cascaded fiber

Abstract

We report a single frequency lasing phenomenon with a narrow linewidth of ~3 kHz in cascaded fiber that is composed of three types of low-loss communication fibers. The Rayleigh scattering of the Brillouin Stokes light created in the middle fiber section along both directions is enhanced by the other two fiber sections. When the Brillouin gain of the middle fiber exceeds the effective loss of the Brillouin stokes light in a roundtrip, a narrow linewidth lasing is observed on the top of the Brillouin spectrum line of the middle fiber. To the best of our knowledge, it is the first report on Rayleigh scattering-assisted Brillouin lasing with single frequency and narrow linewidth in cascaded low-loss communication fibers.

Recent advances in fundamentals and applications of random fiber lasers

“…This narrower bandwidth in turn leads to a much narrower lasing linewidth as compared to the random fiber lasers based on Raman gain. SBS-based random lasing was demonstrated in [72][73][74]. Linewidth narrowing below the SBS gain bandwidth is achieved via the cooperation between Rayleigh scattering and SBS, as shown in [75].…”

Random spaced index modulation for a narrow linewidth tunable fiber laser with low intensity noise

“…The multiple local index modulation points are equivalent as many low finesse random spaced FPIs which added additional loss to laser cavity modes including indexmodulation-induced modes. Only the mode with the highest gain can lase, hence the intensity noise has been reduced significantly compared with previous reported random ring lasers [14][15][16][17][18]. Its relative intensity noise (RIN) is ∼20 dB lower than the Rayleigh scattering of a long-fiber-length-based laser.…”

“…There are two kinds of random fiber lasers based on Er-doped fiber as gain, Brillouin gain or Raman gain. One is the ring configuration laser with a random medium being separated by a circulator, which is similar to a random medium as an injection to a ring laser with Er-doped gain fiber [14][15][16][17]. Another kind is a bidirectional operated random laser [6][7][8]18].…”

Modeling of the spectrum in a random distributed feedback fiber laser within the power balance modes

“…Up to date, a number of different schemes of random DFB fiber lasers were demonstrated [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] . Namely, random DFB fiber lasers can operate in different spectral bands 12,13 , emit higher order Stokes waves [12][13][14] , be tunable 22,23 and multiwavelength 15,19,21 .…”