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What is an Optical Aspheric Surface?

Apr. 13, 2020

What is an optical aspheric surface? Broadly speaking, aspheric surfaces are other surfaces that do not include spherical surfaces and flat surfaces. From an application perspective, aspheric surfaces can be divided into axisymmetric aspheric surfaces, aspheric surfaces with two symmetric surfaces, and free surfaces without symmetry.

Aspheric surfaces are usually divided into quadratic aspheric surfaces and higher-order aspheric surfaces. The secondary aspheric surface is the most widely used in Optical Assemblies and has a special position relative to other types of aspheric surfaces. Secondary aspheric surfaces can be divided into a pair of aspheric surfaces without aberration points and aspheric surfaces without aberration points. The former is widely used in various optical instruments and is the most common aspheric surface. The latter is widely used in optical systems that form deformed images. Higher-order aspheric surfaces can be divided into monotonous meridian curves and non-monotone surfaces.

IR Aspherical Lens

IR Aspherical Lens

Although this kind of freeform surface has lost the characteristic of aspherical axis symmetry, it is still developed regularly around a coordinate origin. There are still rules to follow. There is another type of complex freeform surface that can only be defined by three-dimensional point coordinates. It is widely used in progressive multifocal glasses to achieve the purpose that the power is distributed according to a specific law.

Aspherical Lens Suppliertalked about the technical principle that aspheric lenses are used. The radius of curvature changes with the central axis to improve optical quality, reduce optical components, and reduce design costs. Aspheric lenses have unique advantages over spherical lenses, so they have been widely used in optical instruments, imaging, and optoelectronics industries, such as digital cameras, CD players, and high-end microscopic instruments.

In terms of spherical aberration calibration, aspheric lenses are used to replace spherical lenses. The most obvious advantage is that they can correct the spherical aberration caused by spherical lenses in collimation and focusing systems. By adjusting the surface constant and the aspheric coefficient, the aspheric lens can eliminate spherical aberration to the utmost. Aspheric lenses (light rays converge to the same point to provide optical quality) basically eliminate the spherical aberration caused by spherical lenses (light rays converge to different points, resulting in blurred imaging). Three spherical lenses are used to increase the effective focal length and to eliminate spherical aberration. However, a single aspheric lens (high numerical aperture, short focal length) can be achieved, and simplifies system design and provides light transmittance.

Aspheric lens simplifies the elements involved by optical engineers in order to improve the optical quality, while improving the stability of the system. For example, in a zoom system, usually 10 or more lenses are used (additional: high mechanical tolerance, additional assembly procedures, improved anti-reflection coating), but 1 or 2 aspheric lenses can achieve similar Or better optical quality, thereby reducing the size of the system, increasing the cost rate, and reducing the overall cost of the system. For Customized Aspheric Lenses, please contact us.