Weproposeandexperimentallydemonstrateanovelwavelengthtunableandfrequencyspacing
switchable multi-wavelengthBrillouin fiber laserbyemployingopticalgainandabsorptionduringthe
StimulatedBrillouinscatteringprocess.Thefrequencyspacingcanbeswitchedbyonlyvaryingthe
Brillouin pumppower.Upto16StokeslineswithsingleBrillouinfrequencyspacingareobservedunder
the lowerBrillouinpumppower,and7StokeslineswithdoubleBrillouinfrequencyspacingarerealized
under thehighBrillouinpumppowerbyexploitingtheBrillouinpumpabsorption.Theproposedmulti-
wavelengthlasercanalsobetunedfrom1547to1569nmandhasthepotentialapplicationsintheareas
of opticalcommunicationsandsensing