SINGLE MODE WIDEBAND POLARIZATION MAINTAINING FIBER COUPLER

A single mode wideband polarization maintaining (PM) fiber coupler, including: a first PM fiber having a first core and a pair of first stress members configured to provide a first mechanical stress to the first core; and a second PM fiber having a second core and a pair of second stress members configured to provide a second mechanical stress to the second core; wherein a length of the first PM fiber is fused with a corresponding length of the second PM fiber, wherein at least one geometry among the first core and the pair of first stress members is different from a corresponding at least one geometry among the second core and the pair of second stress members, and the difference in the at least one geometry between the first and second PM fibers causes a frustrated coupling between the first and second PM fibers.