|1105-002||Ball||UV Fused Silica||1.0mm||0.80mm||None||$8.5||2~3 Days|
|1105-005||Ball||UV Fused Silica||2.0mm||1.59mm||None||$8.5||2~3 Days|
|1105-031||Ball||CDGM H-LAK8A||2.5mm||/||None||$5.5||2~3 Days|
|1105-008||Ball||UV Fused Silica||3.0mm||2.39mm||None||$8.5||2~3 Days|
|1105-011||Ball||UV Fused Silica||4.0mm||3.18mm||None||Inquiry||Inquiry|
|1105-014||Ball||UV Fused Silica||5.0mm||3.98mm||None||$10.0||2~3 Days|
|1105-017||Ball||UV Fused Silica||6.0mm||4.78mm||None||$10.0||2~3 Days|
|1105-020||Ball||UV Fused Silica||7.0mm||5.57mm||None||$10.0||2~3 Days|
|1105-023||Ball||UV Fused Silica||8.0mm||6.37mm||None||$12.0||2~3 Days|
|1105-026||Ball||UV Fused Silica||9.0mm||7.16mm||None||$12.0||2~3 Days|
|1105-029||Ball||UV Fused Silica||10.0mm||7.96mm||None||$12.0||2~3 Days|
Ball Lenses are a special form of biconvex lenses which inherit the geometry of a ball (which implies completely spherical surfaces), manufactured from a single material with the optical transmission sited in the wavelength region of interest. The predominant function of ball lenses is light collimation/coupling for optical fibers (e.g. laser to fiber coupling, fiber to fiber coupling), with other versatile possibilities to be incorporated in miniature optics (e.g. Barcode Scanning, Sensors, or as objective lenses, etc.). Ball Lenses could also be considered as pre-forms aspheric lenses. One advantage of a ball lens is its short Back Focal Length (BFL), a trait that cuts down the distance from the optic to the fiber and is exceptionally useful when the installation space is rather tight, and compact dimension could simultaneously reduce the production cost. Additionally, a ball lens is rotationally symmetric, which enhances the ease of aligning and positioning.
Hangzhou Shalom EO provides off-the-shelf Ball Lenses made from N-BK7, UV Fused Silica, and Sapphire with diameters from 1-10mm, and custom Ball Lenses of various substrate materials including Ruby, Ge, ZnSe, and other Optical Glass Materials with high refractive indices. Our Ball Lenses feature compact dimension capability which effectively liberates space limitation and high precision/low spherical aberration. For custom ball lenses, a broad diameter range from 0.3mm to 100mm are available.
Material Selection Guidance:
N-BK7 Ball Lenses:
N-BK7 is a high-quality borosilicate crown glass requisite for the fabrication of optics. It is one of the most prevalent optical glass, and with its transmission range from visible to near-IR low level of inclusions, and chemical/mechanical firmness, is an option whenever the extra benefits of UVFS (e.g. high transmission in the UV region) are not obligatory. It is worth noting that under normal conditions N-BK7 has relatively higher losses through higher absorption and scattering and therefore is more appropriate for applications of low/medium power levels. N-BK7 are designed to adapt to various processing, therefore N-BK7 ball lenses are also ideal pre-forms of Aspheric Lenses.
UV Grade Fused Silica Ball Lenses :
UV Grade Fused Silica is amorphous state silicon dioxide made from fusing SiCl4 stones with high purity oxyhydrogen flame. The most outstanding attribute of UV Fused Silica is its high transmission rate in the ultraviolet region. The low coefficients of thermal expansion contribute to the high thermal stability. Additionally, the material also features high chemical resistance and minimal fluorescence.
Sapphire Ball Lenses:
Optical grade Single Crystal Sapphire (Al2O3) Ball and Half Ball Lenses, with unrivaled surface hardness, great heat resistance, and durability to chemical corrosions, is particularly suitable for operating environments that are subject to high heat. The broad transmission range of Sapphire from 0.15-5.5μm is also impressive. The large Refractive Index of Sapphire suggests decreased spherical aberration.
|Materials||Sapphire, N-BK7, UVFS, Ruby, Ge, ZnSe, High-Refractive-Index Glass||Lens Type||Ball Lens|
|Working Wavelength Range||UV to IR||Irregularity (@663nm)||λ/4|
|Surface Quality||40/20 S/D||Coating||None or Custom AR Coatings|
Calculations of NA and EFL in Ball Lenses:
There are three essential parameters that are crucial for ball lenses and half-ball lenses: Effective Focal Length (EFL), Back Focal Length (BFL), and Numerical Aperture (NA).
EFL is the distance between a plane through the center of the lens and the focal ponit of an initially collimated input beam. EFL of ball lens could be calculated when one is given the refractive index (n) and diameter (D) of the ball lens. The relation ship could be formulated as:
BFL is the distance of the focal point from the lens surface, therefore half the diameter smaller than the EFL. BEF simply equals:
BEF = EFL-D/2
To collimate light properly, it is important that the NA of the ball lens is equal to or smaller than the NA of the fiber optic. The calculation process of NA is complicated:
NA = n0Sinθ = 1/[1+4(nD/4d(n-1))^2]^1/2
(Note: the equation assumes the refractive index outside the ball lens (n0) is 1.) In paraxial approximation, the equation above could be simplified as:
NA = 2d(n-1)/nD