Phase-change material (PCM) embedded heat exchanger assembly for laser diode cooling and systems and methods thereof

A heat exchanger configured to cool an energy output device, and systems, devices, and methods thereof, can comprise a heat exchanger housing and an internal chamber defined in the housing that is configured to be filled with a phase-change material (PCM). The internal chamber can be provided at a first predetermined level inside the housing relative to the top surface of the housing and can extend under a first predetermined portion of the top surface of the housing. The internal chamber can include a plurality of PCM channels configured to be filled with the PCM and to accommodate phase changes of the PCM in multiple phase-change directions. Optionally, the plurality of PCM channels can be defined by a plurality of fins and/or the internal chamber can be accessible to outside the housing via at least one PCM interface configured to receive and pass therethrough the PCM.