  We investigate the physics of the photonic band structures of the moir\'e
patterns that emerged when overlapping two mismatched period uni-dimensional
(1D) photonic crystal slabs. The band structure of our system is a result of
the interplay between intra-layer and inter-layer coupling mechanisms, which
can be fine-tuned via the distance separating the two layers. We derive an
effective Hamiltonian that captures the essential physics of the system and
reproduces all numerical simulations of electromagnetic solutions with high
accuracy. Most interestingly, \textit{magic distances} corresponding to the
emergence of photonic flat bands of the moir\'e lattice are observed. We
demonstrate that these flat band modes at a magic distance are tightly
localized within a moir\'e period. Moreover, we suggest a single-band
tight-binding model that describes the moir\'e minibands, of which the
tunnelling rate can be continuously tuned via the inter-layer strength. Our
results show that the band structure of bilayer photonic moir\'e can be
engineered in the same fashion as the electronic/excitonic counterparts. It
would pave the way to study many-body physics at photonic moir\'e flat bands
and novel optoelectronic devices.
