Fig. 1. (a) Schematic diagram of a chip-integrated fiber sensing system. (b) Optical image of the chip with a driven voltage applied to the LED. (c) Microscope image of the butt-coupling between the optical fibers and chip.

Fig. 2. (a) Schematic diagram of the chip fabrication process, including (I) ITO deposition, (II) mesa definition and etching, (III) electrodes deposition, and (IV) meta pads deposition. (b) Current–voltage (I–V) curve of the LED. The inset shows its C–V curve. (c) Electroluminescence (EL) and response spectrum (RS) of the MQW-based structure. (d) Photocurrent response of the PD under LED radiation with different inject currents. (e) An 8 h stability test of the LED light-emitting intensity.

Fig. 3. Schematic diagram of the fabrication process of a PDMS-packaged fiber sensor.

Fig. 4. Bending sensing performances of the chip-integrated fiber system. (a) The system baseline (pink line) and step-like photocurrent response (blue line) when the bending angle continuously changes from 0° to 40°. (b) The extracted photocurrent values correspond to the bending angles. (c) Photocurrent response under instantaneous bending angle changes. (d) Photocurrent response of the sensing system under a bending angle step of 2°.

Fig. 5. Experimental results of VLC when the monolithic optoelectronic chip serves as a transceiver. (a) Experimental setup of the VLC links for audio and video transmission. (b) Bandwidth of the micro-LED. Comparisons between transmitted and received PRBS signals when the system works in the (c) uplink and (d) downlink states, respectively. (e) Eye diagram at 20 Mbps.

Fig. 6. Comparisons between original and recovered audio signals in the time domain and the frequency domain. (a) Waveform and (b) spectrogram of the original signal. (c) Waveform and (d) spectrogram of the recovered signal.