The past decade witnessed the rapid development of LED based solid-state lighting (SSL) and visible light communication (VLC) systems. However, the relatively low bandwidth (tens or hundreds of MHz) in LEDs limits the data transmission rate. The advent of GaN-based laser-diode offers Gbit/s data rates with high optical power. However, the current approach based on direct-current modulation of c-plane laser diodes suffers from large modulation voltage, transient-heating effect and RC delay.By seamlessly combining waveguide-modulator and laser diode emitting at 448 nm on semipolar-plane substrate, which has considerably reduced polarization fields, a small-footprint, high-speed, low power-consumption device having the SSL-VLC dual-functionalities was demonstrated. Our device shows a high modulation efficiency of 2.68 dB/V, large modulation bandwidth of > 1GHz with a low operating voltage range of 3.5 V. Our approach enables the platform for high data-rate SSL-VLC dual-function lamps for eventual realization of smart-lighting and internet-of-things.
Advantages:
- Voltage modulation (QCSE-based).
- Small area (reduced capacitance).
- Small modulation current (Suppressed transient heating and reduced switching power).
Our
device exhibits a high modulation efficiency (Ron/off/ΔV) of 2.68 dB/V, which is more than double in
reported c-plane modulators (~
1.11 dB/V).