Enhanced Raman amplifier flatness with nonlinear broadening over non-standard transmission fibre

Reflectivity variation in asymmetric random distributed feedback Raman fiber laser

“…This effect takes place with sufficient pump power (depending on the cavity length). Furthermore, the spectral nonlinear broadening is amplified with increasing pump power [29] and reflectivity as demonstrated in figures 4 and 5, respectively.…”

“…Another factor to be considered with regards to spectral broadening is the high nonlinearity coefficient and low anomalous dispersion of the TrueWave fiber at the pump wavelength [15,29] showed that with these characteristics, signal pump is effectively broadened hence producing a smooth broadened Raman gain spectrum. This effect takes place with sufficient pump power (depending on the cavity length).…”

A moment method analysis of the gain spectrum in bi-directionally pumped Raman amplifiers through continuous-spectrum radiation

“…(6) and is appeared in moment functions. The moment functions are symmetric with respect to all lower indices except for the first one.…”

“…The required spectral broadening of emission lines is achieved by using diode lasers without spectrally selective elements like narrowband mirrors or Brag grating. The emission bandwidths of diode lasers in the 14XXnm region without spectrally selective element can be in the range 10-15 nm [6][7][8]. Other methods, such as incoherent pumping [9,10] and highly non-linear fiber (HNLF) broadening [7,8,11], can also be applied to produce broadband pump sources.…”