Optical wireless receiver for data delivery to retinal implant

A very low power optical wireless receiver for use in low rate, short range applications, in general, and for use in retinal prosthesis application, in particular, is proposed. Conventional optical wireless receivers are based on transimpedance amplifier and consume large static power which is not suitable for low power biomedical applications. The proposed design consumes no static power. Robust background current rejection is achieved through the use of modulation in polarization domain. A low power receiver has been designed and simulated in 0.18 μm CMOS technology. It consumes 396 nW with a 1.8V supply at a data rate of 32 Kbit/s with a Figure-of-Merit (FoM) of 12pJ/bit. DC Photocurrent of 0 to 300nA can be rejected with a sensitivity of -52 dB_m. The receiver can be operated at data rate of 512 Kbps with a sensitivity of -40dbm when sampled twice per bit.