  We show theoretically that a broad area bidirectional laser with slightly
different cavity losses for the two counterpropagating fields sustains cavity
solitons (CSs). These structures are complementary, i.e., there is a bright
(dark) CS in the field with more (less) losses. Interestingly, the CSs can be
written/erased by injecting suitable pulses in any of the two
counterpropagating fields.
