The trend toward miniaturization and multi-functionalization of implantable medical devices is shifting the paradigm of medicine from treatment to prevention and precision management; however, it faces a bottleneck due to the energy density limits of batteries. Existing power transfer technologies based on electromagnetic induction or radio frequency cause rapid efficiency degradation and electromagnetic interference issues in micro-scale devices. This paper reviews laser-based optical wireless power transfer technology as an innovative alternative to these issues, with particular emphasis on its potential medical applications. We provide an in-depth analysis of strategies to maximize penetration depth using near-infrared windows and light propagation characteristics within biological tissue, optimization of conversion efficiency through bandgap engineering of silicon (Si) and gallium arsenide (GaAs) based photovoltaic cells, and the latest wavefront shaping and optical phased array technologies to overcome dynamic scattering. Furthermore, by chronologically organizing research trends over the past 20 years, we discuss the paradigm shift from passive devices to active intelligent systems and present the technical and regulatory challenges for clinical adoption based on international safety standards (IEC 60825-1, ISO 14708-1), ultimately providing a technical roadmap for the energy autonomy of next-generation bio-electronic medicine.

Background: Medical lasers have become essential tools in dermatology for both therapeutic and cosmetic applications, treating conditions such as vascular lesions, pigmentation disorders, and scars. The efficacy and safety of these treatments depend on the interaction between laser energy and skin tissues, where laser parameters—power, pulse width, and wavelength—control how heat is generated and distributed.Understanding these interactions is critical to prevent unwanted thermal damage while achieving effective treatment outcomes. Methods: An experimental setup simulating human skin layers was used to measure temperature changes under controlled laser exposure. Analytical calculations and finite element analysis were applied to quantify how variations in laser power, pulse width, and wavelength affect heat generation and distribution in the tissue. Results: Higher laser power and longer pulse widths caused significant increases in skin temperature, indicating stronger thermal effects. Wavelength influenced the depth of penetration and the spatial distribution of heat across skin layers. Additionally, increasing the laser duty cycle led to greater cumulative heating, further elevating tissue temperature during repeated or continuous irradiation. Conclusion Laser parameters, including power, pulse width, wavelength, and duty cycle, critically determine the thermal response of skin tissue. Optimizing these settings can enhance therapeutic outcomes while minimizing the risk of burns, scarring, or other thermal injuries.