Theoretical and experimental analysis of the lateral modes of high-power broad-area lasers

For maximum fiber-coupled power, broad-area (BA) diode lasers must operate with small lateral far field angles. However, these structures are laterally multi-moded, with low beam quality and wide emission angles. We use a combination of device simulation and diagnostic measurements to determine the physical factors limiting the lateral far field angle in state of the art BA lasers emitting at 975 nm. Two-dimensional simulations of the optical field enable the dominant lateral waveguiding mechanisms to be diagnosed. Spectrally resolved near and far field measurements will allow us to determine the nature of the lateral modes.