  Reservoir computing is an analog bio-inspired computation model for
efficiently processing time-dependent signals, the photonic implementations of
which promise a combination of massive parallel information processing, low
power consumption, and high speed operation. However, most implementations,
especially for the case of time-delay reservoir computing (TDRC), require
signal attenuation in the reservoir to achieve the desired system dynamics for
a specific task, often resulting in large amounts of power being coupled
outside of the system. We propose a novel TDRC architecture based on an
asymmetric Mach-Zehnder interferometer (MZI) integrated in a resonant cavity
which allows the memory capacity of the system to be tuned without the need for
an optical attenuator block. Furthermore, this can be leveraged to find the
optimal value for the specific components of the total memory capacity metric.
We demonstrate this approach on the temporal bitwise XOR task and conclude that
this way of memory capacity reconfiguration allows optimal performance to be
achieved for memory-specific tasks.
