Optical Lenses
A Ball Lens can be regarded as a special kind of biconvex lens in sphere shapes. The substrate of ball lenses is often made of a single monolithic optical material, such as optical glass (e.g. N-BK7, UV Fused Silica), sapphire, etc. Ball lenses are primarily used to collimate light or focus lights.
Optical ball lenses are often manufactured in small sizes, typically in the range of a few millimeters or even less than 1 mm (often referred to as microlenses). The reason for this size limitation is due to their fabrication advantages.
For such small dimensions, the spherical geometries of ball lenses make them easier to produce compared to other conventional lens shapes, such as convex or aspheric lenses. This is because ball lenses can be made through precision grinding and polishing, which simplifies the manufacturing process. Unlike conventional lenses that require complex shaping and surface finishing to achieve the desired optical properties, ball lenses naturally form a symmetrical shape with uniform curvature, reducing production complexities and cost.
The major advantages of ball lenses also include superior light collection efficiencies, short focal length, and high numerical aperture (NA), which makes them suitable for fiber coupling and LED applications. Additionally, at these small scales, aligning and mounting traditional lenses can be more challenging, whereas the spherical and symmetric shape of optical ball lenses provides uniform performance in all directions, eliminating the need for precise alignment along a particular axis, offering a simplified solution for focusing and collimating light in integrated optic systems. This makes them particularly useful in applications such as fiber optic communication, laser collimation, and endoscopy.
The most critical parameter of ball lenses is their focal length. The focal lengths of ball lenses are determined by the diameter and refractive index, the calculation formula is as below:
EFL=nD/4(n-1)
Where EFL is the effective focal length of the ball lens, n is the refractive index of the lens material, and D is the diameter of the ball lens.
Half-ball lenses, also called half-ball spheres, are lenses with one flat side and one hemispherical outline, a half-ball lens can be regarded as simply splitting a ball lens in half. The functions of half-ball lenses are also collimation and focusing of light, but the difference between ball lens and half-ball lens is that the half-ball lenses feature a flat side and, therefore are more recommended for space-sensitive designs.
Hangzhou Shalom EO is a professional supplier of Off-the-shelf and Custom Ball Lenses and Half Ball Lenses. We can provide miniature ball lenses and half-ball lenses with a minimum diameter of 0.3mm, and the maximum diameter that we can provide is 300mm. Our stocked ball lenses and half-ball lenses are made of three kinds of optical substrate materials, sapphire, UV fused silica glass, and N-BK7 glass. In addition to the standard sapphire, UVFS, and N-BK7 optical ball and half-ball lenses, we can also provide custom ball and half-ball lenses of diverse sizes and with different focal lengths, where the custom optical ball lenses and half-ball lenses made of various materials such as ruby, Ge, ZnSe, and other high-refractive-index glass ball lenses.
The sapphire ball lens and half-ball lens offer superior hardness and extensive optical transmission range from UV to mid-IR, it is also an optical substrate material with a large refractive index, allowing for more compact optical designs. UV fused silica glass ball and half ball lenses feature low thermal expansion and broad transmission from 195–2100 nm and are especially preferred for their UV light transparencies. The N-BK7 glass ball lenses and half-ball lenses have lower costs compared to sapphire and UV-fused silica ball/half-ball lenses. Combined with its good optical performance to wavelengths from the visible and near-IR spectral region and high machinabilities them the common choice for general applications.
Shalom EO’s ball lenses and half ball lenses are exceptional for versatile applications, including:
