An optical probe includes first and second light guiding components, and a ball lens arranged along an optical axis and enclosed in a sheath having asymmetric optical power. The probe transmits at least two light beams including first and second beams each having a different wavelength. The ball lens has a curved surface and an angled surface arranged such that light is reflected off from the angled surface and focused by the curved surface at a working distance with a beam waist profile having lateral and longitudinal directions. Beam waist locations of the first and second beams are different from each other, and the beam waist profiles of the first and second beams in the lateral direction differs less than the beam waist profiles in the longitudinal direction. This ball lens design compensates for the sheath asymmetric optical power and provides balanced astigmatism and substantially achromatic performance.
