  Over the past decade, integrated quantum photonic technologies have shown
great potential as a platform for studying quantum phenomena and realizing
large-scale quantum information processing. Recently, there have been proposals
for utilizing waveguide lattices to implement quantum gates, providing a more
compact and robust solution compared to discrete implementation with
directional couplers and phase shifters. We report on the first demonstration
of precise control of single photon states on an $11\times 11$
continuously-coupled programmable waveguide array. Through electro-optical
control, the array is subdivided into decoupled subcircuits and the degree of
on-chip quantum interference can be tuned with a maximum visibility of
0.962$\pm$0.013. Furthermore, we show simultaneous control of two subcircuits
on a single device. Our results demonstrate the potential of using this
technology as a building block for quantum information processing applications.
