Mirror Symmetry in Flavored Affine D-type Quivers

We present non-trivial checks of three dimensional mirror symmetry for $\mathcal{N}=4$, $\hat{D}_N$ quiver gauge theories with unitary gauge groups using partition function on a round sphere. Type IIB (Hanany-Witten) realization of these theories and their mirror duals (as world volume gauge theories on coincident D3 branes) involve 1/2-BPS boundary conditions associated with orbifold and orientifold 5-planes respectively, in addition to NS5 and D5 branes. We demonstrate that partition function for a given quiver in this class may be decomposed into distinct contributions from the aforementioned Type IIB ingredients. As a byproduct of this computation, we find a convenient way of deriving the mirror map for a given pair of dual theories.