Adoption of large aperture chirped grating antennas in optical phase array for long distance ranging.

Optical phased array can be widely used in many fields benefiting from its superior performance. We designed and fabricated chirped grating antennas and uniform grating antennas for the optical phased array. The effective aperture of the chirped grating antennas is about twice that of the uniform grating antennas. The chirped grating optical phased array can receive the reflected signal of the object at a distance of 100 m, while the uniform grating optical phased array can only receive 50 m under the same conditions. Additionally, a ranging distance of 25 m is achieved when two chirped grating optical phased arrays are set as the transmitter and receiver.

InGaAs/InP multi-quantum-well nanowires with a lower optical leakage loss on v-groove-patterned SOI substrates.

InGaAs/InP multi-quantum-well nanowires were directly grown on the v-groove-patterned SOI substrate by metal organic chemical vapor deposition. The surface morphology of the nanowires, the thickness of the quantum wells, and the photoluminescence spectra were characterized by scanning electron microscope, transmission electron microscopy, and micro-photoluminescence, respectively. We found in the experiments that the work of removing part of top Si on both sides of the nanowire to further reduce the optical leakage loss could be completed perfectly without complicated processes, such as a lithography process. Numerical simulations showed that the III-V nanowire was able to support an extraordinarily stable optical guided mode with a lower optical leakage loss of 0.21 cm-1 when etching away part of top Si on both sides of the nanowire, and the optical confinement factor of the multi-quantum-well active region was about 8.8%. This approach opens up a way for monolithic photonic integration of III-V compound semiconductors on Si to occur.

1.06-µm InGaAs/GaAs multiple-quantum-well optical thyristor lasers with a PiNiN structure.

InGaAs/GaAs multiple quantum well (MQW)-depleted optical thyristor lasers operating at 1.06 µm with a waveguide-type PiNiN structure is presented for the first time. The optical thyristor lasers clearly show nonlinear S-shaped current-voltage and lasing characteristics. The measured switching voltage and current are 5 V and 1 mA, respectively. The holding voltage and current are 2.6 V and 3.6 mA, respectively. A relatively high output light power of 30 mW per facet at room temperature is achieved. The lasing wavelength is 1.055 µm at a bias current of 80 mA at 25 °C.