Integrated transceiving chip based on RCLED and PIN-PD for plastic optical fiber link

Abstract

In this paper, we propose a monolithically integrated optical transceiving chip (IOTC) scheme by vertically integrating a resonant cavity enhance LED (RCLED) on its top side and a PIN-PD at its bottom side. It can be used for promoting the application of single fiber bi-direction (BiDi) transmission in plastic optical fiber (POF) link. For a fabricated IOTC, the transmitting function is realized by its RCLED unit, which emits light upwards to a POF at 804.6 nm with a FWHM of 4 nm. The receiving function is realized by its PIN-PD unit, which collects the light, while it passing through its RCLED unit, from the same POF. For realizing the transmitting and receiving function simultaneously, firstly, high optical isolation performance between the ITOC’s two units should be realized, which means the RCLED’s backlight should be as little as possible compared with its top emitting light. And the obtained optical isolation level between the fabricated IOTC’s two units is higher than 30 dB. Secondly, high photo-response isolation performance between the ITOC’s two units also need to be realized, which means the RCLED’s photo-response to the receiving light should be as little as possible compared with the PIN-PD’s photo-response. For the fabricated IOTC, it realizes a responsivity of 0.42A/W at the receiving wavelength around 831 nm and a photo-response isolation level of higher than 70 dB between its two units. For dynamic performance, the IOTC’s RCLED unit obtains a 3 dB modulation bandwidth of 2.2 GHz, and its PIN-PD unit obtains a 3 dB photo-response bandwidth of 10.6 GHz. Within the 10.6 GHz bandwidth, the dynamic isolation level between the two units is higher than 30 dB. It should be feasible to be used for constructing in-home single POF BiDi optical link.