Lenses

Longman Optical produces a broad range of precision grade lenses with outstanding specifications. They are made of the best grade material of BK7 optical class, fused silica, sapphire, high index flint glass. The lenses are widely used in the optical industry and have various functions. They can be used for the simple collection of light, the scanning of laser beams, precise imaging and image transfer. Simple lens elements can work either singly or in combination with others. Some of our lenses are customer OEM. We are very competitve both in producing small quantity and large volume customer OEM lenses.

Achromatic Doublets

Achromatic DoubletsAchromatic doublet lenses (“achromat”) are designed to eliminate chromatic and spherical aberrations inherent in singlet lenses. When used on-axis, an achromatic lens focuses an parallel input beam to a perfect “point”, imited only by the effects of diffraction. This performance can be achieved over a broadband of wavelength. Achromatic lenses can be used to collimate and focus laser beams. They can also be used for high-quality imaging on-axis. However, the off-axis performance is significantly.

Specifications:

Focal Length Tolerance: ± 2%
Diameter Tolerance: +0/-0.05 to +0/-0.25 mm
Centration: 3 minutes (depending on diameter and configuration)
Center Thickness Tolerance: ± 0.20 mm (± 0.30 mm for triplets)
Surface Quality: 40/20 – 80/50 (per customer requirements)
Coatings: Standard or custom coatings are available.

Aspherics

AsphericsManufacture aspherical lenses from most available optical glass materials. We have competitive pricing for custom aspherical lenses in prototype or large quantities.

Specifications:

Focal Length Tolerance: ± 2% , ± 3 %
Diameter Tolerance: +0/-0.50 mm
Centration: 6 minutes (depending on diameter and configuration)
Center Thickness Tolerance: ± 0.25 mm
Surface Quality: 80/50 , 120/80
Coatings: Single, Multi-layer and V-coat AR coatings.

Ball Lenses

Ball LensesBall lenses are used for light coupling in fiber-optic applications. The choice of the optical ball lens depends on various parameters such as the diameter of the laser beam, the numerical aperture of the fiber and the wavelength of the light.

We put out these ball lenses from optical glasses to provide a high coupling efficiency when used with fiber optics. They are simple to use as they can be put in contact with the end of the fiber.   

Specifications:

Material: BK7, LaSFN9 glass
Sphericity: /4 at 633nm
Surface Quality: 20-10
Diameter: 1m
Coating (optional): R<1.5% avg per surface, 400-700nm at 0angle of incidence

CCD Lenses

CCD LensesMade to customer specifications.

Cylindrical Lenses

Cylindrical LensesCylindrical lenses are available in either plano-concave or plano-convex configurations. Plano-concave lenses have a negative focal length and are used for image reduction or to spread light. Plano-convex lenses have a positive focal length, which makes them ideal for collecting and focusing light for many imaging applications.

Specifications:

Focal Length: ± 2%
Dimensions Tolerance: +0/- 0.20 mm
Centration: 3 minutes
Center Thickness: ± 0.20 mm
Surface Quality: 40/20 – 80/50
Coatings: Single, Multi-layer and V-coat AR coatings

Fused Silica and Fused Quartz

Fused Silica

Transmission Range: 185-2500nm
Refractive Index: 1.4858@308nm
Low Thermal Expansion Coefficient: 0.54 x 10-6K

Better performance from UV to IR spectrum. Also, it is the best choice for resistance thermal application.

Specifications:

Dimensions Tolerance: +0/-0.10 mm
Flatness: 1/10 waves – 3 waves
Thickness Tolerance: ± 0.10 mm
Surface Quality: 20/10 – 80/50 (per customer requirements)
Materials: Crown glass, Quartz, Fused Silica, Sapphire and Flint glass, etc.

Meniscus Glass Lenses

Meniscus Glass LensesWe can manufacture a wide range of diameters and focal lengths, 1 mm to 300 mm. Lenses can be shaped to your particular requirement. We can provide them mounted or unmounted with standard or custom metal mounts.

  • Plano-convex lenses
  • Bi-concave lenses
  • Bi-convex lenses
  • Bi-concave lenses
  • Meniscus (positive or negative)

Specifications:

Focal Length Tolerance: ± 2%
Diameter Tolerance: +0/-0. 05 to + 0/-0.5 mm
Centration: 3-5 minutes (depending on diameter and configuration)
Center Thickness Tolerance: ± 0.10 mm
Surface Quality: 40/ 20 , 60/40, 80 /50 (per customer requirements) Coatings: Standard or custom coatings

Plano-Concave Glass Lenses

Plano-Concave Glass LensesA lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, concentrating or diverging the beam. A simple lens is a lens consisting of a single optical element.

Specifications:

Focal Length Tolerance: ± 2%
Diameter Tolerance: +0/-0. 05 to + 0/-0.5 mm
Centration: 3-5 minutes (depending on diameter and configuration)
Center Thickness Tolerance: ± 0.10 mm
Surface Quality: 40/ 20 , 60/40, 80 /50 (per customer requirements)
Coatings: Standard or custom coatings

Plano-Convex Lenses

Plano-Convex LensesThis kind of lens has positive focal lengths. They work best when producing real images at near infinite conjugates or where one of the conjugates is virtual. Our optical designers are always available to assist with your special needs large or small quantity requirements.

Specifications:

Dimensions Tolerance: +0.0-0.15mm
Paraxial Focal Length: 2%
Centration: 3 arc minutes
Clear Aperture: >90%
Surface Quality: 60-40 scratch and dig
Bevel: 0.25mm 45B

Rod Lenses

Rod LensesRod Lenses are polished on the circumference and ground on both ends. Optical performance is similar to a cylinder lens, made to customer specifications.

Sapphire Lenses

Sapphire LensesWith >98% transmission with AR coatings on both sides @ 2.94 µm and 2.1 µm,  Sapphire Lenses have surface figures to 1/8 wave, supplied to customers specifications.

Specifications:

Focal Length Tolerance: ± 2%
Diameter Tolerance: +0/-0. 05 to + 0/-0.5 mm
Centration: 3-5 minutes (depending on diameter and configuration)
Center Thickness Tolerance: ± 0.10 mm
Surface Quality: 40/ 20 , 60/40, 80 /50 (per customer requirements)
Coatings: Standard or custom coatings<

Triplet Achromats

Triplet AchromatsWe can supply air spaced or cemented triplets to customer specifications. Please enquire about our capabilities to manufacture these components.