Systems and methods for measuring a physiological parameter of tissue in a patient are provided herein, such as a system to optically analyze tissue of a patient. An example system includes a tissue interface assembly configured to emit an input optical signal into the tissue, receive a reference optical signal and a measurement optical signal from the tissue, and transfer the reference optical signal and the measurement optical signal to the optical link. The optical link is configured to transfer the reference optical signal and the measurement optical signal. The transceiver is configured to receive and convert the optical signals into digital signals.