We demonstrate a novel mesh of Mach-Zehnder interferometers (MZIs) for
programmable optical processors. The proposed mesh, referred to as Bokun mesh,
is an architecture that merges the attributes of the prior topologies Diamond
and Clements. Similar to Diamond, Bokun provides diagonal paths passing through
every individual MZI enabling direct phase monitoring. However, unlike Diamond
and similar to Clements, Bokun maintains a minimum optical depth leading to
better scalability. Providing the monitoring option, Bokun's programming is
faster improving the total energy efficiency of the processor. The performance
of Bokun mesh enabled by an optimal optical depth is also more resilient to the
loss and fabrication imperfections compared to architectures with longer depth
such as Reck and Diamond. Employing an efficient programming scheme, the
proposed architecture improves energy efficiency by 83% maintaining the same
computation accuracy for weight matrix changes at 2 kHz