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Sapphire Ball Lenses and Half-ball Lenses (Stock List)

  • Extreme surface hardness and chemical resistance
  • Transmission Range: 0.15 to 5.5μm
  • Suitable for application from UV to MWIR
  • AR coating available
Inquire for custom product  
Code Types Material Diameter EFL Coating Unit Price Delivery Cart
1105-003 Ball Sapphire 1.0mm 0.57mm None $10.0 2~3 Days
1106-003 Half-Ball Sapphire 1.0mm - None Inquiry Inquiry
1105-006 Ball Sapphire 2.0mm 1.15mm None $10.0 2~3 Days
1106-006 Half-Ball Sapphire 2.0mm - None $10.0 2~3 Days
1105-009 Ball Sapphire 3.0mm 1.72mm None $10.0 2~3 Days
1106-009 Half-Ball Sapphire 3.0mm - None Inquiry Inquiry
1105-012 Ball Sapphire 4.0mm 2.30mm None $12.0 2~3 Days
1106-012 Half-Ball Sapphire 4.0mm - None $12.0 2~3 Days
1105-015 Ball Sapphire 5.0mm 2.87mm None $12.0 2~3 Days
1106-015 Half-Ball Sapphire 5.0mm - None $12.0 2~3 Days
1105-018 Ball Sapphire 6.0mm 3.45mm None $15.0 2~3 Days
1106-018 Half-Ball Sapphire 6.0mm - None Inquiry Inquiry
1105-021 Ball Sapphire 7.0mm 4.02mm None Inquiry Inquiry
1106-021 Half-Ball Sapphire 7.0mm - None Inquiry Inquiry
1105-024 Ball Sapphire 8.0mm 4.60mm None $18.5 2~3 Days
1106-024 Half-Ball Sapphire 8.0mm - None Inquiry Inquiry
1105-027 Ball Sapphire 9.0mm 5.17mm None $20.0 2~3 Days
1106-027 Half-Ball Sapphire 9.0mm - None $21.0 2~3 Days
1105-030 Ball Sapphire 10.0mm 5.75mm None $23.0 2~3 Days
1106-030 Half-Ball Sapphire 10.0mm - None $23.0 2~3 Days

What are Ball lenses and Half-ball lenses:

Ball lenses belong to a special form of biconvex lenses which have the geometry of a ball (sphere). Ball lenses are manufactured from a single optical material with good transmittance in the wavelength region of interest. The conventional applications of ball lenses include focusing light in the field of fibers (e.g. laser to fiber coupling, fiber to fiber coupling), emitters, and detectors, in major to collimate light depending on the geometries of the input light source. Also, ball lenses could be ball pre-forms of aspheric lenses where ball lenses are deformed on purpose to prevent spherical aberrations.

Half-Ball lenses are variants of ball lenses, obtained through cutting the ball lenses in half. Due to the ease of mounting derived from the one flat surface, half-ball lenses are more convenient for applications where space limitations exist and more compact designs are required, such as fiber communication, endoscopes, microscopes, optical pick-up devices, and laser measurement facilities.

There are three essential parameters of ball lenses and half-ball lenses. One is the effective focal length (EFL), which is the distance between a plane through the center of the lens and the beam waist (focus) of a collimated input beam. Another is back focal length (BFL), defined as the distance of the focal point from the lens surface, therefore half the diameter smaller than the EFL. The last is numerical aperture (NA), for collimated incident light, the numerical aperture (NA) of the ball lens is dependent on the size of the ball lens (D), its index of refraction (n), and the diameter of the input source (d). Numerical aperture is proportionate to the resolution of the lens, the larger the NA, the more the light is collected by the lens.

The calculation equations of the EFL, BFL, and NA and shown in the figure below:


Here are some important features of Sapphire:

Sapphire:

Optical-grade Sapphires chosen to produce optical components are Alpha Single Crystal Sapphires, chemical formula Al2O3, with a wide transmission range from 0.225-5.5μm. Sapphire has a hexagonal structure. The lattice constant is a=b=4.758A, c=12.991A, and the refractive index is 1.762-1.770. Its strong covalent bonds contribute to the enduring and solid nature of sapphire. Its Mohs hardness is 9, ranking right after diamond, and its anti-compression strength is between 1.9-24 GPa. Young’s Modulus of sapphire is 380Gpa, which is about twice the magnitude of irons. The melting temperature of sapphire is high,2045 °C, which enables sapphire to be engaged in manifolds of applications requiring high thermal loads.

Sapphire Ball lenses and Half Ball lenses are ideal for demanding applications in the IR spectrum because of wide transmission range of 0.15-5.5μm, superior surface hardness (9 on the Mohs scale, the third hardest mineral, after diamond at 10 and moissanite at 9.5, which means high resistance to scratch and abrasion), high thermal conductivities, outstanding dielectric properties and resistance to common chemical acids and alkalis. In addition, sapphire features a high refractive index, which is advantageous for light collection. Shalom EO offers off-the-shelf and custom Sapphire Ball Lenses and Half Ball Lenses with a maximum diameter of 300mm, AR coatings are available.

Specifications:

MaterialsOptical grade sapphire crystalsDiameter Range~300mm
Diameter Tolerance+0.0/-0.2mmThickness Tolerance+/-0.2mm
Surface Quality60/40 S/DFringes (N)3
Irregularity (delta N)1Centration3'
Chamfer0.1-0.3mmx45 degree

 

Physical and Optical Properties:

Transmission Range0.17 to 5.5 μmRefractive IndexNo 1.75449; Ne 1.74663 at 1.06 μm (1)
Reflection Loss14% at 1.06 μmAbsorption Coefficient0.3 x 10-3 cm-1 at 2.4 μm(2)
Reststrahlen Peak13.5 μmdn/dT13.1 x 10-6 at 0.546 μm(3)
dn/dμ = 01.5 μmDensity3.97 g/cc
Melting Point2040°CThermal Conductivity27.21 W m-1 K-1 at 300K
Thermal Expansion5.6 (para) & 5.0 (perp)x 10-6/K*HardnessKnoop 2000 with 2000gindenter
Specific Heat Capacity763 J Kg-1 K-1 at 293K(4)Dielectric Constant11.5 (para) 9.4 (perp) 、at 1MHz
Youngs Modulus (E)335 GPaShear Modulus (G)148.1 GPa
Bulk Modulus (K)240 GPaElastic CoefficientsC11=496 C12=164 C13=115 C33=498 C44=148
Apparent Elastic Limit300 MPa (45,000 psi)Poisson Ratio0.25
Solubility98 x 10-6 g/100g waterMolecular Weight101.96
Class/StructureTrigonal (hex), R3c





Curves:

1. Transmission of Sapphire at Infrared wavelength range (no coating)

2. Transmission of Sapphire at UV wavelength range ( no coating)


5.0mm Diameter Sapphire Half-Ball Lens

5.0mm Diameter Sapphire Half-Ball Lens

1.0mm Diameter Sapphire Half-Ball Lens

1.0mm Diameter Sapphire Half-Ball Lens

9.0mm Diameter Sapphire Half-Ball Lens

9.0mm Diameter Sapphire Half-Ball Lens