Dia12.7mm CaF2 AR Coated Spherical Double Concave Lens Optical Biconcave Lens

• After-sales Service: Repair, Replace, Refund
• Warranty: 3-Year
• Usage: Lighting, Medical, Optical, Photography, Astronomical
• Model NO.: Biconcave L8
• Type: Concave Lens
• Transmittance: >95%
• Shape: Double Lens
• Material: Optical Glass
• Lenses Color: Clear
• Certification: RoHS, ISO9001
• Customized: Customized
• Coating: HMC
• Dimension: Customized, From 10mm to 500mm
• Thickness: Customized, From 0.2 to 100mm
• Dimension Tolerance: up to 0.02mm
• Thickness Tolerance: up to 0.02mm
• Wedge: up to 20arcsec
• Flatness: 1/2L@633nm
• Surface Quality: 20-10 Scratch-Dig (up to 10-5 Available)
• Focal Length Tolerance: ±1 %
• Surface Roughness: Rq<0.5nm
• Coatings: Ar, Bbar, Customized According to Requi
• Clear Aperture: >90% Centered
• Chamfer: <0.1mm
• Aoi: 0-55deg
• Bevel: Break Sharp Edges
• OEM: Available
• Transport Package: Carton, Blister, Customized
• Specification: Customized
• Trademark: Band-Optics
• Origin: China
• HS Code: 9001909090
• Production Capacity: 100000piece/Month

Product Description

Specification

Product:	Optical Biconcave Lens
Materials:	Optical Grade Glass, N-BK7, UV fused silica, CaF2, ZnSe, ZnS, MgF2, Si, Sapphire, etc.
Diameter:	1.5mm-550mm
Diameter Tolerance:	±0.05 mm (precision ±0.01mm)
Thickness:	0.5mm-100mm
Thickness Tolerance:	±0.05mm (precision ±0.01mm)
Focal Length Tolerance:	±1 %
Surface Quality:	20-10 scratch-dig (up to 10-5 available)
Flatness:	PV<1/4L@ 633nm (up to 1/10L); RMS<1/40L
Surface Roughness:	Rq<0.5nm
Centration:	<3 arcmin (1 arcmin precision)
Center:	ETV<0.008mm
Chamfer:	<0.1mm
Clear Aperture:	≥90 % of Diameter
AOI:	0-55deg
Coatings:	single-layer MgF2, broadband VIS, VIS-NIR, NIR I/II, telecom, or high-energy laser V-coatings (266nm, 355nm, 532nm, 1064nm, etc.)

Key Features

Optical Biconcave Lens

Diverging Light Rays

Bi-concave lenses inherently diverge incident light. A parallel input beam appears to originate from a virtual focal point behind the lens, enabling beam expansion, focal-length adjustment, or uniform illumination.

 

Negative Focal Length

Supplied with negative focal lengths (typical range –30 mm to –1000 mm), these lenses allow precise control over divergence angle and system back-focus. Custom focal lengths available on request.

 

Coating Options

Uncoated: Economical choice for low-power or cost-sensitive setups.

MgF₂ Single-Layer: Reduces average reflection to ≈1.5 % per surface at 550 nm.

Broadband AR: Multi-layer V-coating achieves <0.5 % reflection over 400–700 nm (other ranges available), maximizing throughput in imaging or spectroscopic systems.

 

Applications

Optical Biconcave Lens

1. Laser Beam Expansion & Shaping

Bi-concave lenses are widely used in laser systems to diverge and expand a collimated laser beam. By increasing the beam diameter, they help achieve the required beam size for downstream optics or applications like:

Laser projection systems

Material processing (e.g., cutting or engraving)

Beam shaping before re-collimation with a second lens

 

Note: A bi-concave lens is often used in a Galilean or Keplerian beam expander setup, paired with a convex lens to re-collimate the expanded beam.

2. Focal Length Adjustment & Convergence Correction

In optical assemblies such as telescopes, microscopes, or beam delivery systems, bi-concave lenses are used to:

Increase the effective focal length of the system

Counteract excessive convergence from preceding optics

Fine-tune the image plane location without redesigning the entire system

 

This is especially useful in multi-element lens systems where precise control over ray divergence is needed.

 

3. Photography & Imaging Systems

While not common in standard camera lenses, bi-concave lenses are used in specialized imaging setups to:

Create soft-focus effects or deliberate distortion

Widen the field of view when used in combination with positive lenses

Correct for spherical aberrations or chromatic aberrations as part of a compound lens group

 

They are also used in experimental optics, artistic photography, and custom lens prototyping.

4. Educational & Demonstrative Optics

Due to their simple diverging behavior, bi-concave lenses are frequently used in:

Optics labs to teach ray tracing and lens equations

Demonstrations of virtual image formation

Inspections

Production Line

Company History

FAQ

Q: What are your main products?

A: Optical Components: Aspherical Lenses, Spherical Lenses, Cylindrial Lenses, Lens Assemblies, Optical Windows, Optical Mirrors, Optical Prisms, Optical Filters, and Other Special Shaped Optics......
 

Q: What's your MOQ?

A: Normally one piece. If more, we can talk about discount. You can ship with other parts together .

Q: How about the delivery time?

A: For stocks, within one week after the payment. As to customized products, the delivery time will be negotiated according to your requirements.

 

Q: Can i get a sample to check the quality?

A: YES, we are glad to provide samples for your test. And there is discount for Trade Assurance Sample Order.

 

Q: Can you offer OEM service?

A: YES. We will custom the material, specifications and optical coatings for your optical components as your requirements.

 

Q: How to pay?

A: T/T, L/C, Western Union, Cash, Credit Card, Paypal, Alipay, MoneyGram, Assurance payment......

 

Q: What's the way of shipping?

A: We accept DHL, Fedex, TNT, UPS, EMS, SF and etc. If you have your own express number, it's great.

 

Q: How to guarantee the quality of your products? 

A: 1) Strict detection during each production process. 

2) Advanced metrology solutions: ZYGO, Mitutoyo, Agilent, TAYLOR HOBSON, TRIOPTICS, MOELLER-WEDEL.....

3) Strict inspection on products before shipment and intact product packaging ensured.

 

Q: Any other good service your company can provide?

A: 24-hour after-sale service and long-time maintenance......

Accepted delivery terms: FOB, CIF, EXW, DDU, DDP, Express.....
  Accepted payment currencies: USD, EUR, RMB......
  Accepted Languages: English, Japanese, Chinese, Spanish, Russian.....