Abstract: Systems and methods for using a tag are shown and described. The tag can include a photovoltaic module and an RF module. The photovoltaic module receives an impinging optical transmission and converts at least a first portion of the optical transmission into electrical energy and a second portion of the optical transmission into data. The RF module communicates directly or indirectly with the photovoltaic module. The RF module receives the electrical energy from the photovoltaic module and in response modifying a characteristic of the RF module to generate a backscatter modulation signal.