A mains electricity (AC-powered) device assembly in which input energy is used to excite a diode to emit a high-power [i.e., not considered low-level laser therapy (LLLT)], therapeutic laser beam, typically of visible red-light, intended for oncological photodynamic therapy (PDT) and photochemical internalization (PCI). It is part of a drug-device therapy that combines a pharmaceutical photosensitizer with photoactivation for local cancer treatment. The software-controlled device is designed to deliver cylindrical diffusing outputs and/or frontal diffusing output for surface treatment and/or for interstitial treatment.