Systems and methods for applying optical signals onto tissue of a patient are provided herein. In one example, a system to optically analyze tissue of a patient is provided. The system includes a measurement system configured to transfer source optical signals over an optical link, receive measurement optical signals over the optical link, and identify a value of a physiological parameter of the patient. The optical link comprises a first source portion with a first link property configured to carry the source optical signals and a second source portion with a second link property coupled to the first source portion and configured to carry the source optical signals. The system includes a tissue interface assembly configured to receive the source optical signals transferred over the optical link, emit the source optical signals into the tissue, and receive the measurement optical signals from the tissue for transfer over the optical link.