Classic lasers directly emit coherent beam without the need for additional optics. Output aperture of most lasers might seem to emit light into all directions,

Classic lasers directly emit coherent beam without the need for additional optics. Output aperture of most lasers might seem to emit light into all directions, but most of the output power is concentrated into the direction of the resonant cavity. Due to manufacturing tolerances low power laser diodes tend to produce somewhat irregular output beam (both diverging and uneven) which is then compensated for using some external optics that also serve to set required width of the final output beam. It is impractical to convert light from some arbitrary "point-like" source (ie. LED) into beam that has low divergence by lenses or similar optics.