Multi-junction cascade 905 nm vertical cavity surface emitting lasers with high power density

Abstract

Aiming at three-dimensional (3D) sensing applications such as LiDAR, high power density five-junction cascaded vertical cavity surface emitting lasers (VCSELs) with 905 nm wavelength are designed and fabricated. The maximum power conversion efficiency is 55.2% for an individual VCSEL emitter with 8 μm oxide aperture. And the maximum slope efficiency of the device is 5.4 W/A, which is approximately 5 times that of traditional single-junction VCSEL with the same aperture. Under the condition of narrow pulse (pulse width 5.4 ns, duty cycle 0.019%) injection, the peak output power of 19-element array (20 μm oxidation aperture for each element) reaches 58.3 W, and the corresponding power density is as high as 1.62 kW/mm². The devices with various apertures (8–20 μm) are characterized. The results show that the maximum slope efficiencies of all these devices are greater than 5.4 W/A and the maximum PCE is higher than 54%. These high-performance VCSEL devices can be used as ideal light sources for 3D sensing applications such as LiDAR.