A light-triggered transponder includes one or more of photo cells, a clock recovery circuit and a reverse antenna system. The clock recovery circuit (CRC) includes a photoconductor with a source terminal, a drain terminal for receiving a voltage, the photoconductor resistance varying with received light intensity. The CRC is configured to generate a recovered clock. A reverse antenna system connected to at least one photo cell and configured to transmit data. The photoconductor configured to produce a modulated voltage signal from an incident modulated light incident. The CRC can include an amplifier coupled to the source terminal of the photoconductor via a capacitor for receiving the modulated voltage signal and outputting an analog signal generated from the voltage signal. The CRC can include an inverter coupled to the amplifier and configured to digitize the analog signal of the amplifier.