A variable optical attenuator (VOA) array is described, which may achieve a power adjustment speed of 1 ms or less for each channel. The VOA array includes: a substrate; and a plurality of VOAs disposed on the substrate, where the plurality of VOAs have trenches therebetween, and a VOA in the plurality of VOAs includes: a phase change material (PCM) layer, where a state of the PCM layer is selectively in a crystalline state, an amorphous state, or a mixed state based on temperature of the PCM layer, and variation of the state of the PCM layer is used for adjusting an output power of an optical signal input into the VOA array; a controller configured to change the temperature of the PCM layer; and a mirror layer configured to reflect the adjusted optical signal of the

Described herein are systems and methods for dynamically configuring memory using Optical Circuit Switching (OCS). As electrical processing units such as accelerators are limited by their available bandwidth, providing disaggregated memory can help expand memory and enable better processing performance. Providing OCS devices to dynamically reconfigure processor-to-processor and processor-to-memory connections enables flexible reconfiguration of the disaggregated memory and improve performance of the system.