An optical surgical probe includes a cannula; a light guide within the cannula, configured to receive a light beam from the light source, to guide the light beam to a distal end of the light guide, and to emit the light beam at the distal end of the light guide; and a multi-spot generator at a distal end of the cannula, the multi-spot generator having a faceted proximal surface with oblique facets, configured to receive the light beam emitted at the distal end of the light guide and to split the received light beam into multiple beam-components, and a distal surface through which the multiple beam-components exit the multi-spot generator, wherein the proximal surface of the multi-spot generator is micro-structured with a modulation length smaller than a wavelength of the light beam in order to reduce the reflectance of light back into the probe.