We report the first spectroscopic study using a low temperature near-field scanning optical microscope. We have studied an array of GaAs/AlGaAs cleaved edge overgrowth quantum wires. The three luminescence peaks originate from different structures in the sample: The (001)-oriented multiple quantum wells, the (110)-oriented single quantum well, and the quantum wires. The linewidth of the quantum wire emission is related to roughness in the (110)-oriented single quantum well. Quenching of the multiple quantum wells and single quantum well emission near the quantum wires is attributed to diffusion of photoexcited carriers into the wires. Applied Physics Letters is copyrighted by The American Institute of Physics.