The application and function of optical filter in daily life
High Precision Optical Components-Optical filter is a relatively foreign concept for many people, as if it is a little distant from our daily life, but in fact, it is not. A careful look at the surrounding environment and life, we will find that many aspects of life are closely connected with the filter, today High Surface Accuracy Optical Components Supplier will share about the application and the weight of the weight of the role of the optical filter in our daily life.
Optical filter and our life has been inseparable, let's take a look at the existence of optical filter in life and where they are? Such as vision correction of myopia have minus reflection filter on the mirror, car mirrors with high reflection filter, widely used in the business office projector core components but also brings together a variety of filters, went to the hospital to check body using biochemical detector is one of the core parts of monochromator many are using narrowband filter, digital camera is used in the long wave pass filter, short wave pass filter, all kinds of optical instruments, liquid crystal displays and anti-counterfeiting technology, optical communication, laser technology and so on all is closely connected with the development of filter technology. It can be said that without the development of filter technology as the basis, many modern emerging technologies are difficult to achieve the current achievements.
A filter is a layer or multi-layer dielectric film or metal film plated on an optical element or an independent substrate to change the characteristics of light wave transmission. Using the characteristics of light wave in the transmission of these thin films, such as transmission, absorption, scattering, reflection, polarization, phase change, and so on, and then design and manufacture of various filter products to achieve the purpose of scientific and engineering applications. Manufacturing filter technology is a complex engineering technology, involving many professional technical fields, including vacuum acquisition technology, vacuum measurement technology, computer-aided design technology, optical characteristics testing technology, electronic circuit technology, material characteristics testing and preparation technology.
An optical device used to select the desired radiation band. There are two categories: color filters, which are flat glass or gelatine of various colors with transmission bandwidth of several hundred angstroms, often used in broadband metering or mounted in stellar spectrographs to isolate overlapping spectral levels. Its main feature is that the size can be made quite large. The membrane filter is further divided into two kinds: membrane absorption filter and membrane interference filter. The former is chemically etched on a specific material substrate so that the absorption line is at the desired wavelength.
Generally through the longer wavelength, used as infrared filter. The latter is a kind of low-grade, multi-stage series solid interferometer formed by alternating metal-media-metal films with high or low refractive index of a certain thickness by vacuum deposition method on a certain substrate. The choice of membrane material, thickness and series mode is determined by the required central wavelength and transmission bandwidth.
Lambda's interference filters are currently available at any wavelength from ultraviolet to infrared. The peak transmittance of metal-dielectric membrane filter is not as high as that of all-dielectric membrane, but the secondary peak and side band problems of the latter are more serious. There is also a circular or elongated variable interference filter in the thin-film interference filter, which is suitable for space astronomical measurement. In addition, there is a dual-color filter, which is placed at a 45° Angle with the incident beam, and can decompose the beam into two different colors perpendicular to each other with high and uniform reflection and transmission, suitable for multi-channel multi-color measurement. Interference filters generally require normal incidence, when the incidence Angle increases, to the short wave direction. This feature can be used to calibrate the central wavelength within a certain range.