Hybrid telescope for optical beam delivery and related systems and methods

Optical coherence tomography (OCT) imaging systems are provided including a source of broadband optical radiation coupled to a sample arm of the OCT imaging system; a beam shaping optical assembly in the sample arm, the beam shaping optical assembly being configured to receive optical radiation from the source as a beam of optical radiation and to shape the spatial profile of the beam of optical radiation; a scan mirror assembly coupled to the beam shaping optical assembly; and objective lens assembly coupled to the beam shaping optical assembly. The beam shaping optical assembly includes a lens assembly configured to change a NA of the OCT system without changing a focus; to change a focus of the OCT system without changing a NA of the system; or to change both the NA and the focus of the OCT system responsive to a control input.