An optical radio frequency (RF) signal generator , the signal generator comprising: a Stimulated Brillouin Scattering (SBS) pump laser segment that includes a first SBS pump laser and a second SBS pump laser each generating SBS laser light at different respective frequencies; a TE/TM dual comb resonator segment comprising a comb optical resonator coupled to the first SBS pump laser and the second SBS pump laser , wherein the comb optical resonator segment generates a pair of counter-propagating optical frequency combs, wherein a first comb of the pair of counter-propagating optical frequency combs is transverse electric (TE) mode polarized and a second comb of the pair of counter-propagating optical frequency combs is transverse magnetic (TM) mode polarized; and a filter resonator segment configured to provide feedback to the TE/TM dual comb resonator segment to lock a the pair of counter-propagating optical frequency combs at the same frequency or to a fixed frequency offset with respect to each other, the filter resonator segment comprising a tunable optical filter , wherein the optical filter comprises a pair of add-drop optical ring filter resonators that each receive the dual optical comb signal from a codirectional coupler , wherein each of the add-drop optical ring filter resonators is thermally adjustable to pick-out a single line from each of the two combs present in the dual optical comb signal , wherein the filter resonator segment is configured to output a discrete tuned RF signal output based on a comb line pair in the pair of counter-propagating optical frequency combs that includes a single comb line from each of the pair of counter-propagating optical frequency combs, wherein a frequency of the output RF signal is varied as a function of the difference between the frequencies of the comb line pair passed by the tunable optical filter to an optical detector . a Stimulated Brillouin Scattering (SBS) pump laser segment that includes a first SBS pump laser and a second SBS pump laser each generating SBS laser light at different respective frequencies; a TE/TM dual comb resonator segment comprising a comb optical resonator coupled to the first SBS pump laser and the second SBS pump laser , wherein the comb optical resonator segment generates a pair of counter-propagating optical frequency combs, wherein a first comb of the pair of counter-propagating optical frequency combs is transverse electric (TE) mode polarized and a second comb of the pair of counter-propagating optical frequency combs is transverse magnetic (TM) mode polarized; and a filter resonator segment configured to provide feedback to the TE/TM dual comb resonator segment to lock a the pair of counter-propagating optical frequency combs at the same frequency or to a fixed frequency offset with respect to each other, the filter resonator segment comprising a tunable optical filter , wherein the optical filter comprises a pair of add-drop optical ring filter resonators that each receive the dual optical comb signal from a codirectional coupler , wherein each of the add-drop optical ring filter resonators is thermally adjustable to pick-out a single line from each of the two combs present in the dual optical comb signal , wherein the filter resonator segment is configured to output a discrete tuned RF signal output based on a comb line pair in the pair of counter-propagating optical frequency combs that includes a single comb line from each of the pair of counter-propagating optical frequency combs, wherein a frequency of the output RF signal is varied as a function of the difference between the frequencies of the comb line pair passed by the tunable optical filter to an optical detector . <EOS>