Plano-Concave and Plano-Convex Lenses: Spherical Singlets

Plano-concave and plano-convex lenses are the basic building blocks of most optical systems. Each has one flat surface and one curved surface. The concave form has negative power and diverges incoming light. The convex form has positive power and brings light to a focal point. Wavelength Opto-Electronic manufactures both types, along with meniscus, bi-concave and bi-convex lenses, in a range of optical materials. Production runs from standard to high precision specifications, and custom designs are available when a catalogue part doesn’t fit your system.

Plano-concave lenses: diverging and expanding

A plano-concave lens spreads light as it passes through. That makes it the usual choice when you need to enlarge a beam or widen a field of view.

• Laser processing. In beam expansion setups, a plano-concave element diverges the laser beam before a positive lens collimates it at a larger diameter. You’ll find this arrangement in laser cutting and engraving systems.
• Telescopes and imaging optics. A plano-concave lens can act as a corrector, compensating for aberrations introduced by other elements in the optical path.
• Wide-angle imaging. In photographic and camera assemblies, negative elements help capture a broader field of view.

Plano-convex lenses: focusing and collimating

A plano-convex lens converges light. It is the standard element for focusing a collimated beam to a point, or for collimating light from a point source.

• Machine vision and camera optics. Plano-convex elements are common in camera lens assemblies, where convergence is central to image formation. Oriented correctly, a plano-convex lens keeps spherical aberration low and image quality sharp.
• Microscopy and life-science instruments. Plano-convex lenses provide magnification in microscopes, so you can observe fine detail in small specimens.
• Projection systems. These lenses form focused images on screens and other surfaces.
• Magnifiers and inspection aids. Simple positive lenses enlarge small objects for close examination.

The two forms work together. A concave element widens a field of view, expands a beam or corrects aberrations. A convex element focuses, collimates and magnifies. Many systems pair them, such as a Galilean beam expander or a corrected multi-element imaging lens.

Choosing the right part

The catalogue lists each part number by design wavelength, diameter, effective focal length, back focal length, center thickness, edge thickness, material, assembly type and product type. The full searchable table on this page lets you filter on any of these columns.

A few points to settle before you shortlist parts:

• Sign and magnitude of power. Decide whether the element should converge or diverge light, and what focal length your layout needs.
• Design wavelength and material. Match these to your source, whether it is a visible LED, a machine-vision illuminator or a laser line.
• Mechanical envelope. Diameter, center thickness and edge thickness all affect mounting and clearance in your housing.
• Precision grade. Standard-grade parts suit many prototyping and general imaging tasks. High-precision production is the better fit when surface quality and tolerances drive system performance.
• Variant. If a plano form doesn’t meet your aberration or packaging goals, a meniscus, bi-concave or bi-convex lens may be the better choice.

Why order through Wavelength Optics USA

Wavelength Optics is the US arm of Wavelength Opto-Electronic. Working with us gives you a US-based point of contact for parts manufactured by the parent company.

• Local support. You work with a team in your region who understands US engineering and procurement workflows.
• Fast quoting. Send part numbers from the catalogue or a custom prescription, and we will turn around a quotation.
• Technical consultation. If you are unsure whether a plano-convex or a bi-convex lens suits your focusing path, or which material fits your wavelength, our team can help you narrow the selection. We can also connect you with Wavelength’s optical design capability for custom lenses.

Use the spec table to shortlist part numbers, then request a quote from Wavelength Optics USA to discuss your application.