Watt-level beam combined diode laser systems in a chip-scale hybrid photonic platform

Scaling up the power of on-chip diode lasers is of great importance for many emerging applications, such as integrated nonlinear optics, remote sensing, free space communication, infrared countermeasure, and light detection and ranging (LIDAR). In this manuscript, we introduce and demonstrate photonic integrated circuits (PIC) based beam combining methods to create power scalable, integrated direct diode laser systems. Traditional laser beam combining, including coherent beam combining (CBC) and wavelength beam combining (WBC), usually requires free space or fiber optical components, leading to bulky and complex systems. Instead, PIC based beam combining methods can greatly reduce the cost, size, weight, and power consumption (CSWaP) of next generation direct diode laser systems. We experimentally demonstrate four channel chip-scale CBC and WBC with watt-level on-chip power by using III/V-Si₃N₄ hybrid integration. Our results show that PIC based beam combining is very suitable for power scaling in a chip-scale platform.