Performance evaluation of a low power optical wireless link for biomedical data transfer

We report on an experimental low power transcutaneous optical telemetric link (TOTL) for high speed biomedical data transfer. By decreasing the bandwidth to data rate ratio, a silicon photodiode with large active size can be used to significantly increase transmission efficiency as well as misalignment tolerance. Additionally, a custom-designed transimpedance amplifier (TIA) with low input referred noise and a modified on-off keying with a custom designed low power VCSEL (vertical cavity surface emitting laser) driver are used to further reduce the required power consumption. The proposed system transmits data up to 75 Mbps through 6 mm thick tissue, in the presence of a 4 mm misalignment while achieving a BER better than 10^-5, with a power consumption lower than 2.8 mW.