Highly sensitive monolithic optoelectronic receiver with large-area avalanche photodiode for optical wireless communication at low data rates

Abstract

A highly sensitive monolithic optical receiver, applicable in optical fiber and wireless communication is presented. The proposed chip is capable of processing data rates of up to 10 Mb/s and offers compatibility to standard CMOS logic by creating full 3.3-V output swing. The photodetector of the system is carried out as a large-area fully integrated avalanche photodiode with a diameter of 800 µm and a high responsitivity to red light with a wavelength of 675 nm. The receiver features pseudo differential signal processing with offset cancellation feedback to achieve desensitization to background light irradiation usually appearing with optical wireless communication. Additionally, common-mode feedback was implemented to prevent pulse width distorted output signals. Measurements at 2.5, 5, and 10 Mb/s reveal high sensitivities of -50.4, -47.65, and -42.7 dBm, respectively, for BER<10⁻⁹ in dark conditions. For the design, a 0.35-µm CMOS process was chosen.