Sapphire Convex Lens

Plano-convex sapphire lenses for focusing, collimation and demanding UV, visible and IR optical applications.

Microwork manufactures custom sapphire convex lenses and plano-convex sapphire lenses for optical systems where focusing performance, mechanical durability, thermal stability and chemical resistance are required.
A sapphire convex lens is typically used to focus or collimate light in optical, laser, imaging, sensor and harsh-environment systems. Compared with common optical glass, sapphire provides higher hardness, better scratch resistance, excellent chemical stability and strong thermal performance.
Sapphire convex lenses are often considered for applications involving high pressure, vacuum, high temperature, corrosive atmospheres, abrasive environments or systems where the lens surface must resist long-term wear and contamination.

Typical Applications

Common applications include:

• Laser focusing and collimation
• UV, visible and IR optical systems
• Imaging and sensor optics
• Medical optical devices
• High-pressure optical systems
• Vacuum optical assemblies
• High-temperature observation systems
• Aerospace and industrial optical components
• Corrosive or chemically aggressive environments
• Protective focusing optics for harsh operating conditions

Available Lens Types

Available sapphire convex lens types may include:

• Plano-convex sapphire lenses
• Bi-convex sapphire lenses, subject to design review
• Small sapphire convex lenses
• Sapphire micro-optics
• Custom convex sapphire optical components
• Coated sapphire convex lenses
• Sapphire focusing lenses for UV, visible or IR applications

Custom diameter, focal length, radius, center thickness, edge thickness, surface quality and coating requirements can be reviewed according to your drawing or optical design.

Typical Specifications

Material: Optical-grade single-crystal sapphire / Al2O3

Lens type: Plano-convex, bi-convex or custom convex sapphire lens

Diameter: Custom sizes available upon drawing review

Focal length: Custom focal length available depending on lens geometry and optical design

Radius of curvature: Custom radius available upon requirement

Center thickness: Custom center thickness available according to lens design

Edge thickness: Custom edge thickness available depending on diameter and curvature

Surface quality: 60/40, 40/20 or 20/10 depending on optical requirement

Surface accuracy: Custom surface accuracy available depending on optical design

Centration: Custom centration available upon requirement

Clear aperture: Defined according to drawing and optical requirement

Edge finish: Fine ground, chamfered or polished edges

Coating: Anti-reflective coating, dielectric coating or wavelength-specific coating available upon requirement

Wavelength range: UV, visible or IR applications depending on design and coating

Application: Focusing, collimation, imaging, laser, sensor, medical, vacuum, high-temperature or corrosive environment use

Plano-Convex Sapphire Lens Design

Plano-convex sapphire lenses are commonly used when a positive focal length is required. They can be used to focus collimated light or collimate light from a point source, depending on the optical system design.
The lens performance is affected by diameter, focal length, radius of curvature, center thickness, surface quality, centration and coating. For sapphire lenses, these parameters should be reviewed carefully because sapphire is more difficult to grind and polish than many common optical glasses.
For best performance, the orientation of the curved and flat surfaces should be selected according to the optical path, incident light condition and system design.

Sapphire Convex Lens vs Common Optical Glass Lens

Sapphire convex lenses are selected when mechanical durability, scratch resistance, chemical resistance and thermal stability are more important than low material cost.
Common optical glass may be more cost-effective for standard optical systems where harsh-environment durability is not required. Sapphire is preferred when the lens may be exposed to high pressure, high temperature, vacuum, corrosive media, mechanical contact or abrasive particles.
Because sapphire is extremely hard, complex curvature, small diameter, tight centration, high surface quality and special coatings can increase manufacturing difficulty, lead time and cost.

Coating Options

Sapphire convex lenses can be supplied with coating options depending on wavelength, transmission requirement and operating environment.
Available coating options may include:
• Anti-reflective coating
• UV, visible or IR wavelength-specific coating
• Dielectric coating
• Partial reflector coating
• Custom coating design based on optical requirement
Coating performance should be reviewed together with wavelength range, angle of incidence, surface quality, operating temperature and environmental exposure.

Engineering Considerations

When designing a sapphire convex lens, engineers should consider focal length, radius of curvature, center thickness, edge thickness, surface quality, centration, coating durability, clear aperture, mounting method and operating environment.
Small lenses, steep curvature, thin edges, tight centration, high surface quality and special coating requirements can significantly affect manufacturability and cost.
Mounting stress should also be reviewed carefully. Excessive clamping force, poor edge support or uneven mechanical stress may cause chipping, cracking or optical alignment issues.
For early-stage projects, please provide the drawing, lens type, diameter, focal length, radius, thickness, surface quality, centration requirement, coating requirement and wavelength range.

Information Needed for Quotation

To review a custom sapphire convex lens, please provide:
• Drawing or optical specification
• Lens type: plano-convex, bi-convex or custom convex lens
• Diameter
• Focal length
• Radius of curvature
• Center thickness and edge thickness
• Surface quality requirement
• Surface accuracy requirement
• Centration requirement
• Coating requirement and wavelength range
• Edge finish or chamfer requirement
• Operating temperature, pressure or environmental conditions
• Quantity and inspection requirement

Need a Custom Sapphire Convex Lens?

Send us your drawing, focal length, radius, surface quality, coating requirement and wavelength range. We can help review manufacturability, material suitability and key technical risks before quotation.