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Peak power difference between odd-and even-order BSL as a fraction of RPP toward FWP ( f r ) (RPP = 1000 mW, BP wavelength = 1555 nm, BP power = 5 dBm).
Source publication
This publisher’s note amends the author list and Acknowledgments of a recent publication [Opt. Express 23, 25570 (2015).10.1364/OE.23.025570].
Contexts in source publication
Context 1
... the right structures will be those with at least 21 dB discrepancies between odd-and even-order lines to achieve an improvement in BS combs characteristics compared with the results achieved in our previous study [9]. Figure 4 shows the relation between average discrepancy between peak power of odd-and even-order BSL with fraction of RPP toward FWP ( f r ). This measurement is done by subtracting the average peak power values of odd-and even-orders BS combs in decibel scale. ...
Context 2
... the right structures will be those with at least 21 dB discrepancies between odd-and even-order lines to achieve an improvement in BS combs characteristics compared with the results achieved in our previous study [9]. Figure 4 shows the relation between average discrepancy between peak power of odd-and even-order BSL with fraction of RPP toward FWP ( f r ). This measurement is done by subtracting the average peak power values of odd-and even-orders BS combs in decibel scale. ...
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Citations
... Several challenges have been carried out to optimize the performances of 10 GHz spacing MBRFL especially number of channels [14,15] and flat bandwidth [12][13][14][15][16]. Other important characteristics of concern are OSNR [ [16][17][18] and channel spacing [19][20][21][22][23][24][25][26]. Nevertheless, one of the major challenges is to achieve uniform 10 GHz spacing Stoke lines over a wider bandwidth domain with outstanding OSNR [16][17][18]27]. ...
... In their setup, a 50/50 NALM configuration generates 443 channels with 16.5 dB OSNR. Concurrently, there have been numerous successful methods for MBRFL with 20 GHz spacing, such as optimizing Raman pumping ratios using various couplers have also been studied [25]. In this scheme, the 50/50 coupler offers 212 channels with around 28 dB OSNR. ...
... In the laser structure, a bi-directional Raman pumping scheme is realized by dividing the RPU through a variable optical coupler and splicing it to the 12 km DCF through two 1480/1550 nm wavelength selective couplers (WSC1 & WSC2). According to the results attained in our previous report [25], couplers with splitting ratios of 50/50, 90/10, and 95/5 are only connected individually between these components since generation of 20 GHz spacing with high maximum power discrepancy between odd-and even-order Stoke lines through these couplers was achieved. The second DCF coil with a length of 2.7 km at the other side of the cavity together with one physical mirror provides a significant Rayleigh scattering effect which is necessary for generation MBRFL with 10 GHz spacing. ...
We purpose and demonstrate the switchable multi-wavelength Brillouin–Raman fiber laser (MBRFL) through a bi-directional Raman pumping scheme. The laser structure is arranged in a linear cavity by including a physical mirror at one side of the cavity. The switching operation for MBRFL with single- and double-wavelength spacing is implemented by optimizing the Raman power distribution through a variable optical coupler. This effect on feedback power of the physical mirror provides the difference between odd- and even-order Stoke lines’ maximum power on different sides of the cavity with 10 GHz and 20 GHz spacing. A 90/10 coupler is found to be the optimal. Up to 460 flat-amplitude lines within only a 0.5-dB flatness range, average −5 dBm Stokes peak power (SPP), 10 GHz frequency spacing, and an average optical signal-to-noise ratio (OSNR) of 26 dB are observed. All the counted laser lines are spread across a 37 nm bandwidth. Simultaneously, 170 Stoke lines with overall −2 dBm SPP, 28 dB OSNR, and 20 GHz frequency spacing are attained on other side of the cavity. These are achieved when the Raman pump power is set only at 900 mW. To date, this is the simplest cavity design with the flattest spectrum and highest output power for both wavelength spacing and excellent OSNR achieved in multi-wavelength fiber lasers that incorporate a single low-power Raman pump unit.
... To increase the number of generated Brillouin combs, the combinations of rare-earth ions doped gain or Raman gain with Brillouin gain are commonly used [12][13][14][15][16]. Among these, multiwavelength Brillouin-Raman fiber laser (MBRFL) show significant advantages in terms of ultrabroad multiwavelength bandwidth and excellent flatness [17][18][19][20]. ...
... During the past few decades, MBRFLs operating in the conventional C-band fiber transmission window have concentrated the most substantial interest and now well-developed [17][18][19][20]. In principle, by adopting the hybrid Brillouin-Raman gain, the MBRFLs can be realized at arbitrary wavelengths in the transparent window of the used passive fibers. ...
Multiwavelength Brillouin-Raman fiber laser (MBRFL) features broadband multiwavelength generation with flat-amplitude and high optical signal to noise ratio (OSNR), which has great potential in optical fiber communication applications. Till now, the spectral regions of MBRFLs are mostly concentrated at conventional C- and L-band and the tunability of MBRFL is limited by using the Raman pump with fixed wavelength. Here, by utilizing wavelength-agile random fiber laser which can emit tunable lasing at 1.2 µm band as the Raman pump, we experimentally demonstrate the tunable MBRFL in the O-band for the first time, to the best of our knowledge. At Raman and Brillouin pump powers of 920 mW and -3 dBm, respectively, up to 90 Stokes lines with 0.13 nm wavelength spacing and >13 dB OSNR can be obtained when the Raman and Brillouin pump wavelength are set at 1231 nm and 1300 nm, respectively. Moreover, by tuning the wavelength of Brillouin pump from 1295 nm to 1330 nm, tunable MBRFL can be achieved with similar multiwavelength generation bandwidth by simultaneously tuning the Raman pump wavelength, and the number of Stokes lines are beyond 85 across the tuning range. The bandwidth of the demonstrated O-band MBRFL is also the widest wavelength span ever reported for multiwavelength Brillouin fiber lasers at 1.3 µm band. Our work indicates that the use of wavelength-agile random fiber laser as Raman pump in MBRFL can provide an effective way to extend the spectral regions of MBRFL and also improve the tunability performance of MBRFL.
... Several challenges have been carried out to optimize the performances of 10 GHz spacing MBRFL especially number of channels [15,16], and flat-amplitude bandwidth [13][14][15][16][17]. Other important characteristics of concern are OSNR [ [17][18][19], and channel spacing [20][21][22][23][24][25][26][27]. Nevertheless, one of the major challenges is to achieve uniform 10 GHz spacing Stoke lines over a wider bandwidth domain with outstanding OSNR [17][18][19]28]. ...
... In their setup, a 50/50 NALM configuration generates 443 channels with 16.5 dB OSNR. Concurrently, there have been numerous successful methods for MBRFL with 20 GHz spacing, such as optimizing Raman pumping ratios using various couplers have also been studied [26]. In this scheme, the 50/50 coupler offers 212 channels with around 28 dB OSNR. ...
... The discussion is initiated by explaining the light propagation behaviors at different side of the cavity arrangement. With respects to other earlier reports [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], the main achievement of this research work is to introduce novel improvements to simplicity, flatness, Stokes-OSNR (S-OSNR), spectrum bandwidth, and SPP for both wavelengths spacing. ...
We purpose and demonstrate the switchable multi-wavelength Brillouin–Raman fiber laser (MBRFL) through a bi-directional Raman pumping scheme. The laser structure is arranged in a linear cavity by including a physical mirror at one side of the cavity. The switching operation for MBRFL with single- and double-wavelength spacing is implemented by optimizing the Raman power distribution through a variable optical coupler. This effect on feedback power of the physical mirror provides the difference between odd- and even-order Stoke lines’ maximum power on different sides of the cavity with 10 GHz and 20 GHz spacing. A 90/10 coupler is found to be the optimal. Up to 460 flat-amplitude lines within only a 0.5-dB flatness range, average -5 dBm Stokes peak power (SPP), 10 GHz frequency spacing, and an average optical signal-to-noise ratio (OSNR) of 26 dB are observed. All the counted laser lines are spread across a 37 nm bandwidth. Simultaneously, 170 Stoke lines with overall -2 dBm SPP, 28 dB OSNR and 20 GHz frequency spacing are attained on other side of the cavity. These are achieved when the Raman pump power is set only at 900 mW. To date, this is the simplest cavity design with the flattest spectrum and highest output power for both wavelength spacing and excellent OSNR achieved in multi-wavelength fiber lasers that incorporate a single low-power Raman pump unit.
... By including this, the hybrid structure of MBRFL has been greatly recognized in 10 GHz and 20 GHz spacing with different performances [4][5][6][7][8][9][10][11][12]. For example, employing a fully-open (mirrorless) BRFL cavity resulted in generating a wide-span multi-wavelength laser with 20 GHz spacing [12][13][14][15][16][17][18][19][20][21][22]. Other important characteristics of concern are OSNR [10,15,16,22], and stability [23]. ...
... For example, employing a fully-open (mirrorless) BRFL cavity resulted in generating a wide-span multi-wavelength laser with 20 GHz spacing [12][13][14][15][16][17][18][19][20][21][22]. Other important characteristics of concern are OSNR [10,15,16,22], and stability [23]. In these approaches, the power discrepancies between odd-and even-order Brillouin Stoke lines (BSLs) were significantly high. ...
... In addition, based on our previous study in Refs. [14,15], we have found that the longer length of DCF can primarily be attributed to the stronger Rayleigh scattering effect occurring inside the fiber. This particular characteristic is favorable for the specific work being conducted in our research. ...
A simple high flat amplitude multi-wavelength Brillouin–Raman fibre laser (MBRFL) with 10 GHz spacing and excellent optical signal-to-noise ratio (OSNR) in C-Band spectral region is demonstrated. The laser consists of a linear cavity in which 12 km dispersion compensating fiber (DCF) in addition to 49 cm Bismuth-oxide Erbium doped fiber (Bi-EDF) are employed as a gain medium for amplification. The impact of Raman pump power distribution through changes in coupling ratio on amplitude flatness is carried out by comparing the peak power discrepancy between odd- and even-order Brillouin Stoke lines. This is the main property that allows the efficient controlling of gain propagation between lasing lines that is vital for Stokes flattening initiation and other output spectra characteristics. The attainment of MBRFL with outstanding OSNR necessitates the utilizing of Bi-EDF as a noise suppressor. By utilizing a 50/50 coupler, 354 identical channels together with uniform Brillouin Stokes linewidth within only 0.3-dB maximum power difference between adjacent channels is generated. The average OSNR and Stokes power are 28 dB and -5 dBm respectively when the RPP is set at 1300 mW. To date, this is the highest flatness 10 GHz spacing MBRFL with outstanding OSNR attained in MBRFL that incorporate only a single Raman pump unit.
... Nevertheless by utilizing a fully open cavity [8], the problem can be addressed. The growth of over 200 Stokes numbers are accomplished with an average OSNR of 24 [10] and 27.5 dB [11]. The first represents 32.5 nm MBW that is estimated at 5 dB peak power variation. ...
... The main objective of this research is to determine the right parameters responsible for the optimization of channel flatness [6,17,18] with exceptional qualities. These include the number of Stokes lines and its corresponding bandwidth [6,10,11] as well as a reasonable OSNR [7]. (1). ...
... As minimum ( ) RG z is achieved at z L = together with the depletion process, the Rayleigh scattering elements of odd-orders BS lines at the output tap are not significant. This justifies the formation of 20 GHz (0.158 nm) cascaded SBS shifts [10,11] as illustrated clearly in Fig. 4(a). At the outset of this assessment, several investigations to determine the best selection of pumping criteria that satisfy the research objectives are implemented. ...
We discover the technique of controlling the flatness in signal amplitude of a multiwavelength Brillouin-Raman fiber laser by employing an air-gap outside of the cavity. The structure that is adjustable within sub-millimeter length behaves as flexible optical feedback that provides modifiable portions of multiple Fresnel reflectivities. This is the main benchmark that allows the efficient management of gain competition between self-lasing modes and Brillouin Stokes waves that is vital for self-flattening initiation. When setting the Brillouin pump wavelength at 1529 nm and the air-gap distance to 0.4 mm, 296 Stokes lines are produced with a channel spacing of 0.158 nm. The lasing bandwidth is 46.60 nm that covers from 1529.16 to 1575.76 nm wavelength. In this case at Raman power of 950 mW, the intense Brillouin pump power of 2 dBm saturates the cascaded higher-orders lasing lines. As a result, the overall peak power discrepancy is maintained at just 1.8 dB where an average optical-signal-to-noise ratio of 20 dB is realized. To date, this is the widest bandwidth with the flattest spectrum attained in multiwavelength fiber lasers that incorporate a single Raman pump unit.
... The exploitation of nonlinear optical effects has been utilized efficiently in the construction of multi-wavelength fiber lasers [1][2][3][4]. Amongst these, the Brillouin-Raman effect has been regarded as one of the best solutions with several important advantages [5][6][7][8]. These include stable multi-wavelength operation at room temperature with extremely broad workable wavelength band. ...
... These include stable multi-wavelength operation at room temperature with extremely broad workable wavelength band. A number of attempts have been carried out to optimize the performances of multi-wavelength Brillouin-Raman fiber laser (MBRFL) especially number of channels [6,7] and flat-amplitude bandwidth [5,9,10]. Other important characteristics of concern are optical signal-to-noise ratio (OSNR) [11,12], channel spacing [6,[13][14][15], and stability [16]. ...
... In our earlier work that implemented an 11 km length DCF with an inclusion of 30 cm strand Bismuth-Erbium-doped fiber [6], a MBRFL with 20 GHz spacing is reported which yields 195 Stokes lines with 26 dB OSNR. In the same setup that employs only 7.2 km length DCF [7], investigations on Raman pumping distribution around Bi-directional and 100% forward directions are completed. In this case, the implementation of symmetrical coupler is the best choice when the optimization of 20 GHz spacing is the subject of main objective. ...
We propose and demonstrate a new multi-wavelength Brillouin-Raman fiber laser with switchable 10 and 20 GHz spacing. This is achieved by proper adjustments of optical coupling ratios that are incorporated in the design which consists of an enhanced nonlinear amplifying fiber loop. By utilizing a 50/50 coupler, 443 flat amplitude channels with 10 GHz spacing is realized. On the other hand, a 99/1 coupler is feasible for 20 GHz spacing which yields 215 lasing lines. In both cases, the average optical signal-to-noise ratio (OSNR) are 16.5 dB (50/50 coupler) and 24 dB (99/1 coupler). Wide multi-wavelength bandwidth, flexible wavelength spacing, and high number of channels with excellent OSNRs are achieved using only a single Raman pump unit through a simple construction.
A simple switchable multiwavelength Brillouin–Raman fibre laser (BRFL) was demonstrated. The laser was arranged in a half-open cavity configuration including a physical mirror device with an adjustable reflectivity at one side of the laser cavity. The impact of the feedback power adjustment on frequency switching was carried out by comparing the peak power difference between odd- and even-order Stokes lines. Up to 468 flat-amplitude lines with a 10 GHz frequency spacing and average optical signal to noise ratio (OSNR) of 33 dB were observed with mirror reflectivity values of ∼15% up to 60% at a 1534 nm Brillouin pump power of 7 dBm and 0.9 W Raman pump power of 0.9 W. – Under the same pumping conditions, setting the mirror reflectivity at its OFF state (where reflectivity is nearly 0%) allows for up to 242 lines with 20 GHz spacing to be realized, with ONSR values of ∼35 dB.
