The present disclosure relates to optical systems and vehicles, which may incorporate lidar sensors. An example optical system includes a light-emitter device configured to emit emission light. The optical system also includes an optical element including a first surface and an opposing second surface. The first surface includes a diffusing surface configured to diffuse the emission light to form diffused light. The second surface includes a focusing surface. A combination of the first surface and the second surface are configured to provide an intensity profile of light emitted within a field of view of the optical system.