a) Microlens
Micolens are small lenses with a diameter smaller than 1 mm, they can work by diffraction, refraction or a combination of these two. When arranged regularly on a single substrate they form a microlens array. In order to be considered a good quality lens, microlenses must have qualities such as to low wavefront aberrations, consistency of focal length and pitch across the array, durability and low price. (Daly 2001)
Microlens arrays have several applications, such as CCD arrays, digital projectors, photocopiers, mobile-phone cameras, 3D imaging, displays and light field photography. Some of these applications have been around for many years. Recently, due the expansion of manufacture technology, new utilizations are being studied …show more content…
(Montilla, Puga et al. 2015). As it is illustrated in figure 1 below, in a regular camera there is only one lens and only one pixel is captured, however in a plenoptic camera there is the camera lens, the microlens array and an image sensor. In order to work, the microlens array is placed in the focal plane of the camera main lens and the image sensor is put in the microlens array focal plane, so when the light passes through the array, it reaches many pixels. This way it is possible to obtain depth and the image can be digitally refocused after it was taken. (Trujillo-Sevilla, J. et al. …show more content…
When exposed to UV light from a specific wavelength and a photomask, the substrate ends up with the geometric pattern from the photomask. Although this technique has been used successfully in the literature, it is restricted because the substrate must be sensitive to UV light or mixed with a solvent that is sensitive. This last technique was used in (Beinhorn, Ihlemann et al. 1999)’s research, where the substrate poly methyl methacrylate (PMMA) was mixed with a sensitiser diphenyltriazene (DPT) and then a UV laser was used to form the microlenses by single pulse illumination. Another example of UV-light use is in UV-assisted roller imprinting which is known as one of the most efficient replication techniques. (Wu, Yang
Micolens are small lenses with a diameter smaller than 1 mm, they can work by diffraction, refraction or a combination of these two. When arranged regularly on a single substrate they form a microlens array. In order to be considered a good quality lens, microlenses must have qualities such as to low wavefront aberrations, consistency of focal length and pitch across the array, durability and low price. (Daly 2001)
Microlens arrays have several applications, such as CCD arrays, digital projectors, photocopiers, mobile-phone cameras, 3D imaging, displays and light field photography. Some of these applications have been around for many years. Recently, due the expansion of manufacture technology, new utilizations are being studied …show more content…
(Montilla, Puga et al. 2015). As it is illustrated in figure 1 below, in a regular camera there is only one lens and only one pixel is captured, however in a plenoptic camera there is the camera lens, the microlens array and an image sensor. In order to work, the microlens array is placed in the focal plane of the camera main lens and the image sensor is put in the microlens array focal plane, so when the light passes through the array, it reaches many pixels. This way it is possible to obtain depth and the image can be digitally refocused after it was taken. (Trujillo-Sevilla, J. et al. …show more content…
When exposed to UV light from a specific wavelength and a photomask, the substrate ends up with the geometric pattern from the photomask. Although this technique has been used successfully in the literature, it is restricted because the substrate must be sensitive to UV light or mixed with a solvent that is sensitive. This last technique was used in (Beinhorn, Ihlemann et al. 1999)’s research, where the substrate poly methyl methacrylate (PMMA) was mixed with a sensitiser diphenyltriazene (DPT) and then a UV laser was used to form the microlenses by single pulse illumination. Another example of UV-light use is in UV-assisted roller imprinting which is known as one of the most efficient replication techniques. (Wu, Yang