We experimentally determine the lasing mode(s) in optically pumped semiconductor nanowire lasers. The spatially resolved and angle-resolved far-field emission profiles of single InP nanowire lasers lying horizontally on a SiO2 substrate are characterized in a microphotoluminescence (μ-PL) setup. The experimentally obtained polarization dependent far-field profiles match very well with numerical simulations and enable unambiguous identification of the lasing mode(s). This technique can be applied to characterize lasing modes in other type of nanolasers that are integrated on a substrate in either vertical or horizontal configurations.
Keywords: Fourier space imaging; Nanowire lasers; far-field characterization; mode characterization; semiconductor nanowires.