Ideal for fiber optic application, involving focusing of light in fiber or fiber coupling. Available in variety of material like BK7, SF11, quartz and ruby. As the ratio of diameter of beam entering the lens (d) to the diameter of the ball (D) increases the back focal length increases. It is desirable to have low back focal length for fiber coupling application, and so high index glass is preferred. However, quartz ball lenses are preferred for their chemical stability. Ruby lenses are best suited for harsh atmosphere like datum spheres etc.

Ideal for fiber optic application, involving focusing of light in fiber or fiber coupling. Available in variety of material like BK7, SF11, quartz and ruby. As the ratio of diameter of beam entering the lens (d) to the diameter of the ball (D) increases the back focal length increases. It is desirable to have low back focal length for fiber coupling application, and so high index glass is preferred. However, quartz ball lenses are preferred for their chemical stability. Ruby lenses are best suited for harsh atmosphere like datum spheres etc.