SPHERICAL VS. ASPHERIC LENSES

HOW THEY’RE USED IN IMAGING APPLICATIONS

Optical Lenses are often categorized by their shape. Two common surface shapes are spherical and aspherical. Each offers unique characteristics that make it suitable for different use cases.


A spherical lens has a spherical surface and uniform radius of curvature across the entire lens. Deviating slightly from a spherical shape, an aspherical lens has a surface that gradually changes curvature from center to edge. Because the difference between a true sphere and an aspherical lens can be slight, not all aspherical lenses can be distinguished from spherical lenses by the naked eye. Aspherical lenses that are noticeably non-spherical may have an inflection between the center and the edge of the lens.

Here you’ll learn about the advantages of aspherical lenses, as well as their industries and applications.

Benefits of Aspherical Lenses

The main benefit of aspherical lenses is that they can be made to produce no spherical aberration, which all spherical lenses produce to some degree. To minimize spherical aberration when only spherical lenses are available, a designer must use at least two lenses that are designed with offsetting amounts of spherical aberration so that the combination works better than any single spherical lens. Since an aspherical lens produces no spherical aberration,  a single aspherical lens might replace two or three spherical lenses while producing better image quality.

Aspherical lenses also counteract other aberrations by adjusting the aspheric coefficients and conic constant of the curved lens surface. In spherical lens designs, increasing the f/# of the design may be necessary to improve resolution by limiting off-axis aberrations. However, increasing the f/# reduces the light-gathering ability of the system. By contrast, using aspherical lenses enables a high throughput system with a low f/# while maintaining good image quality. 

Applications and Industries for Aspherical Lenses

Aspherical lenses offer greater precision, improved efficiency, and increased aperture size, making them ideal for various applications in diverse industries.

Applications

Aspherical lenses help collimate light into a beam with rays as parallel as possible. They are often used to make objective lenses in optical assemblies lighter and smaller while providing a high level of performance. Reducing the number of total optical elements, aspherical lenses improve image quality. Typical applications include:

  • Cameras
  • Smartphones
  • Laser-enabled devices and equipment
  • Microscope objectives
  • Surgical equipment

Since every application is different, it is best to choose a custom aspherical lens to fit your exact needs. Specialized applications, in particular, require custom lenses designed for the specific size, performance, and budget of the project. Factors to consider include project timeline, budgetary constraints, expected production volumes, and performance requirements.  

Industries

Aspherical lenses are increasingly critical to the imaging, optics, and photonic industries due to the advantages they offer compared to traditional spherical lenses. Aspherical lenses are also widely found in the automotive, medical, entertainment, and aerospace industries. 

Why JML?

JML Optical has designed and fabricated high-quality aspherical glass lenses for over 50 years. By optimizing our manufacturing operations to reduce wait times, we meet strict quality standards and maximize production yields. 

As a precision engineered custom optical solution provider, JML offers optical and optomechanical design, glass and metal fabrication, thin-film coating, rapid prototype, metrology, environmental testing, and complete assembly services. 

As part of the top 10% of optical manufacturers in the U.S., JML Optical is headquartered in the world’s optical and imaging center: Rochester, NY. We solve optical challenges in the aerospace, automotive, defense, medical, life sciences, entertainment, imaging, and semiconductor industries.  

To discuss your aspherical lens or other optical needs, contact us today.