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Ball Lenses

  • Broad diameter range: 0.3mm to 100mm
  • Substrate Materials: Sapphire, N-BK7, UV Fused Silica, Ruby, Ge, ZnSe, and other High-Refractive-Index Glass
  • Coating Options: None or AR Coatings
  • Applications: fiber coupling, objective lenses for endoscopes, bar code scanning, and sensors, pre-forms of Aspheric Lenses
Inquire for custom product  
Code Types Material Diameter EFL Coating Unit Price Delivery Cart
1105-001 Ball N-BK7 1.0mm 0.73mm None $5.5 2~3 Days
1105-002 Ball UV Fused Silica 1.0mm 0.80mm None $8.5 2~3 Days
1105-003 Ball Sapphire 1.0mm 0.57mm None $10.0 2~3 Days
1105-004 Ball N-BK7 2.0mm 1.47mm None $5.5 2~3 Days
1105-005 Ball UV Fused Silica 2.0mm 1.59mm None $8.5 2~3 Days
1105-006 Ball Sapphire 2.0mm 1.15mm None $10.0 2~3 Days
1105-031 Ball CDGM H-LAK8A 2.5mm / None $5.5 2~3 Days
1105-007 Ball N-BK7 3.0mm 2.20mm None $5.5 2~3 Days
1105-008 Ball UV Fused Silica 3.0mm 2.39mm None $8.5 2~3 Days
1105-009 Ball Sapphire 3.0mm 1.72mm None $10.0 2~3 Days
1105-010 Ball N-BK7 4.0mm 2.93mm None $5.5 2~3 Days
1105-011 Ball UV Fused Silica 4.0mm 3.18mm None Inquiry Inquiry
1105-012 Ball Sapphire 4.0mm 2.30mm None $12.0 2~3 Days
1105-013 Ball N-BK7 5.0mm 3.67mm None $5.5 2~3 Days
1105-014 Ball UV Fused Silica 5.0mm 3.98mm None $10.0 2~3 Days
1105-015 Ball Sapphire 5.0mm 2.87mm None $12.0 2~3 Days
1105-016 Ball N-BK7 6.0mm 4.40mm None $7.5 2~3 Days
1105-017 Ball UV Fused Silica 6.0mm 4.78mm None $10.0 2~3 Days
1105-018 Ball Sapphire 6.0mm 3.45mm None $15.0 2~3 Days
1105-019 Ball N-BK7 7.0mm 5.14mm None $7.5 2~3 Days
1105-020 Ball UV Fused Silica 7.0mm 5.57mm None $10.0 2~3 Days
1105-021 Ball Sapphire 7.0mm 4.02mm None Inquiry Inquiry
1105-022 Ball N-BK7 8.0mm 5.87mm None $7.5 2~3 Days
1105-023 Ball UV Fused Silica 8.0mm 6.37mm None $12.0 2~3 Days
1105-024 Ball Sapphire 8.0mm 4.60mm None $18.5 2~3 Days
1105-025 Ball N-BK7 9.0mm 6.61mm None $7.5 2~3 Days
1105-026 Ball UV Fused Silica 9.0mm 7.16mm None $12.0 2~3 Days
1105-027 Ball Sapphire 9.0mm 5.17mm None $20.0 2~3 Days
1105-028 Ball N-BK7 10.0mm 7.34mm None $7.5 2~3 Days
1105-029 Ball UV Fused Silica 10.0mm 7.96mm None $12.0 2~3 Days
1105-030 Ball Sapphire 10.0mm 5.75mm None $23.0 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.

  • Working Wavelength Range: 350nm to 2200nm 
  • Refractive Index: 1.51680 @ 587.5618 nm
  • Thermal Expansion: 7.1 x 10-6/K

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.

  • Working Wavelength Range: 200nm to 2200nm 
  • Refractive Index: 1.458
  • Thermal Expansion: 0.57 x 10-6/℃

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.

  • Working Wavelength Range: 170nm-5500nm
  • Refractive Index: 1.77
  • Compressive Strength (psi): 300,000
  • Thermal expansion: 5.6x10-6/K (parallel), 5.0x10-6/k (perpendicular)

Specifications:

Materials Sapphire, N-BK7, UVFS, Ruby, Ge, ZnSe, High-Refractive-Index Glass Lens Type Ball Lens
Diameters 0.3mm-100mm Sphericity Standard 2μm
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:

EFL= nD/4(n-1)

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

6.0mm Diameter Sapphire Ball Lens

6.0mm Diameter Sapphire Ball Lens

5.0mm Diameter N-BK7 Ball Lens

5.0mm Diameter N-BK7 Ball Lens

4.0mm Diameter UV  Fused Silica Ball Lens

4.0mm Diameter UV Fused Silica Ball Lens