Microlens

A microlens is the miniaturized form of a conventional lens. It is found in nature, but also in the art.

Nature

In nature microlenses are, inter alia in the visual organs of small animals, such as insects,. Even -dimensional arrays of lens groups are known.

The diffraction of light, X-rays and similar waves of crystals can also be understood as a micro-lens. This natural effect is especially used in materials science to back to close to the structure of the crystal lattice of the material. See also diffraction grating.

Technology

, For the technology as with all miniaturized objects, mostly the problems of manufacture and assembly in the target object, the central question.

Applications of industrial micro-lenses are:

• Laser lenses
• Photography and photographic effects
• Microscopy, sensor and measurement technology
• Visual aids.

In the broadest sense, one can understand the elements of a planar Fresnel lens, as used for example in an overhead projector, as an array of microlenses. The structure that is independent of the Fresnel zone plate can be regarded as a functioning lens also miniaturized and is then placed just under the generic term microlens.

Microlenses on semiconductors for photodetection have the particular advantage that they take up very little space and are manufactured industrially. However, since they only have a fraction of the surface and only partially the same quality as conventional lenses so that the light output and thus reduces the sensitivity and the selectivity is reduced to adjacent pixels. For night shots, such sensors are without further upstream optics so only to a very limited suitable. Furthermore, describe photographer limitations of suitability if, in connection with the use of very high-speed wide -angle lenses, over parts of the image has a significantly oblique incident light beam, as the sensitive elements are small in size and are mostly in the linear focus of the individual lenses. An enlargement of the sensor element, however, would increase the predicted noise and extraneous light portion. The development of sensors to determine the direction of incidence of the light seems so possible.

Digital photo expert Henner Helmers writes on its pages, among other things to a Super CCD sensor manufacturer Fuji following:

" In the sensor of the S20, the two cells are no longer together, but the small ones are shifted into the gaps between the large and have their own" microlens ". Advantage: the large can be larger and thus more sensitive to light! → less noise! "

Newer developments have also realized the microlenses in the liquid form.