The demand for energy is increasing exponentially over the world, while Fossil fuel reserves begin to deplete. To sustain development, the supply of energy continuously required. Finding new regenerative energy sources, such as biomass, geothermal energy, or solar energy, etc. and cannot deplete with time. Amongst all, solar energy is essential and fulfills the future needs of energy. Several developed technologies solar energy for domestic use like Fresnel lenses. Fresnel Lenses were actually for concentrating solar energy. The Fresnel lenses theory is not new, and its popularity is growing due to an increase in its applications and improvements in material and manufacturing techniques.
The invention of Fresnel Lenses
Fresnel lenses offer high optical efficiency with low cost and weight and us as solar concentrators. From the 1960s, the Fresnel lens concentrators are useful in solar energy. Due to this feature, the development of Fresnel lenses in commercial solar energy is still widespread and ongoing. That’s why its use is expanding rapidly, and found in highly sophisticated optical. Fresnel lenses solved many severe optical problems and introduced new designs consideration. Although the Fresnel lenses theory is not new, their popularity is growing due to improvements in material and manufacturing techniques.
Working Principle of Fresnel Lenses
The principle behind the Fresnel lenses’ concept is that the direction of propagated light, unless scattered, cannot change in the medium. Instead, the rays of light deviate at the surface of the medium. The material in the center of lenses only increases the weight and volume of the system. For creating annual rings of the curved profile, grooves are cut into the glass pieces, and on releasing becomes conventional. Due to this function, when conventional optical lenses compared to Fresnel lenses, Fresnel lenses offer better-focusing performance. Furthermore, higher groove density allows the more excellent image quality, while lower density provides better efficiency.
Fresnel Lenses Making
Georges-Louis Leclerc de Buffon proposed the idea of Fresnel lenses in 1748. The approach was later adopted by Augustine-Jeans in 1827 and used in 1823 for the first time. Where the refraction occurs, it maintained the curved surface. Fresnel lenses made up of several concentric rings etched into the plastic. The thin and light-weighted construction of lenses is available in different sizes. Because of their ability to gather excellent light, there are useful in various applications. Fresnel lenses consist of simple lens elements, and concentric rings appropriately assembled on a flat surface to provide short focal lengths. Methods of designing Fresnel lenses are easy to process and have excellent optical performance. Fresnel Lenses Theory widely used.
How Are Fresnel Lenses Better than other lenses?
While comparing different lenses, observation reveals that the Fresnel lens is cheaper than any other lens and can be made with a considerable area. The circular section of the Fresnel lens has the same curved surface as the normal lens. But the correspondence present in the normal lens is removed from the Fresnel lens, to make the Fresnel lens flat. The focus point of every ring in the Fresnel lens is the same as the core of the ring in the normal lens. As a result, the Fresnel lens produces the same image as the normal lens created. Most of the area of Fresnel lenses can be made appropriately by plastic.
Uses and Advantages of Fresnel Lenses
Light Gathering Applications
Fresnel lenses are mostly useful for light gathering applications, emitter or detector setups, and condenser systems. Fresnel lenses are useful as image formulation, projection, or magnifier lenses in the illumination system. It is helpful for searchlights and lighthouses to concentrate light I relatively narrow beams. Because of the thickness and weight, large scale beacon lenses of solid glass are almost impossible to manufacture. The lightest Fresnel lenses usually polished and assembled from the appropriate glass.
Home Maintenance and Photovoltaic Cells
One of the most common uses of Fresnel lenses is the collection of Sunlight. Concentration with these lenses is ideal on the heating surface and photovoltaic cells. For instance, Fresnel lenses are used for home maintenance, such as pool and home heating, depending on the amount of collected light. Collection of light is common in all solar applications, but the Fresnel lenses are cheaper, thinner, and lightweight than others, so they are more suitable. Fresnel lenses are unique optical lenses, making it an ideal tool for providing a variety of optical designs.
Useful in Light Houses
Modern Fresnel lenses consist of refractive elements. Many of the lighthouses have both reflecting and refracting elements. The inner components are the sections of refraction, and the outer elements of sections are reflections. Because of the reflection of the silvered mirror, the internal reflection is useful for avoiding the light loss.
Cheaper in cost and lighter in weight
Fresnel lenses have many advantages, like reducing the lens thickness and reduce the material cost; similarly, the weight reduction results in less assembling and mounting expenses. High aperture lenses give high-value design freedom, and large diameter lenses (up to 50 “) can be replaceable with expensive conventional mirrors. Fresnel Lenses Theory widely used.
Useful in Overhead Projectors
Fresnel lenses are most useful at a specific distance, and when they are mostly aspheric. Every overhead projector (OHP) uses a large Fresnel lens to focus the light rays from a substage to collect the light through the flashed transparency. The Fresnel lens gives the same light on all areas, and the transparency directly sits on the Fresnel lens.
For magnification purposes
Fresnel lenses can use anywhere that a large area shaft of insensitive quality is required, while the small size of the plastic, Fresnel lenses magnifies the area for reading the fine print, and they are much lighter than other kinds of the glass lens.
For the lighting system in TVs and Cameras
Fresnel lenses are of great use in lighthouses where no other optics give excellent performance. So, fresnel lenses have many applications like usage in traffic lights and TVs, photography with a compact camera, lightweight, and hand-held magnifier lenses. Fresnel Lenses Theory widely used.
For Making Good Quality Glasses
It is also useful in glasses, Polyvinyl chloride (PVC) membrane commonly used to correct strabismus, eye condition, work as a high power lens. Also used for children with severe eye problems, because of lightweight it is suitable for children and adults. It can capture more light from the light source, and allow the light from the lighthouse over the greater distance. Fresnel Lenses Theory widely used.