A light source structure includes a vertical cavity surface-emitting laser (VCSEL) device having a top surface and at least one side surface substantially perpendicular to and adjoining the top surface. The VCSEL device is configurable to output directed emission of light through the top surface. The light source structure also includes a light barrier surrounding at least a top portion of the VCSEL device and separated from the at least one side surface. The light barrier is configured to receive spontaneous emission out of the VCSEL device through the at least one side surface.