A multi-cladding optical fiber includes a core that conveys visible light used by a scanner for imaging a site within a patient's body, and an inner cladding that conveys high-power light, such as infrared light, used for providing therapy to site. The distal end of multi-cladding optical fiber is driven to scan the site when imaging or rendering therapy using an actuator. High-power light is coupled into inner cladding at proximal end of optical fiber using several different techniques. Some techniques use an axicon to direct the high-power light into the inner cladding, while visible light is coupled directly into the core. Another technique uses a multimode optical fiber in a coupling relationship with the multi-cladding optical fiber, to transfer high-power light from a core of the multimode fiber into the inner cladding of the multi-cladding optical fiber.