In the laser industry, it is inevitable that you will inevitably contact the laser with your eyes, so the importance of laser protective glasses is reflected. The role of laser protective glasses is mainly to prevent laser damage to the eyes, because the laser energy is highly concentrated, which is harmful to the eyes. The harmful effect is great, and there is even the risk of blindness, so laser operators must wear laser glasses for protection.
But in the face of the laser problems that are almost endless in life today, and the particularity of the use of lasers, do we really have a clear understanding of the use and protection of lasers? The function of laser glasses is to prevent the damage and influence caused by laser on us to a great extent.
Laser protective glasses classification
Absorption protective glasses, reflective protective glasses, composite protective glasses, lens design explosion Protective glasses, photochemical reaction protective glasses, glass-ceramic protective glasses, etc.
Commonly used functions of various types of laser protective glasses
absorbent protective glasses
Various absorbents are added to the glass or plastic lens to absorb the laser light and make it impermeable.
Reflective protective glasses: A set of high refractive index dielectric film is plated on the lens. When light hits the dielectric film, all the reflected light on the interface has the same phase , To strengthen the light reflection of this wavelength, not only can reflect the laser to protect the glasses, but also have a high transmittance to other visible light.
Composite protective glasses: Composed of two reflective dielectric films, separated by a layer of color-absorbing glass in the middle, to suppress unwanted internal reflection between the two reflective films. This kind of glasses has relatively good protection performance against laser lens laser, and has a large safety factor, which is suitable for the protection of high and medium power lasers.
Explosive protective glasses: Coat a layer of explosives on the lens. When the intensity of the incident laser reaches a certain value, it is quickly detonated to shield the laser. It is used in the military to prevent laser weapons from harming the eyes. Each type of laser protective goggles has its own characteristics. Generally, it can only prevent lasers of one wavelength, and a few can prevent lasers of two or more wavelengths. Therefore, suitable laser goggles must be selected according to the laser used.
In the design of machine vision system, the most important thing is to obtain a higher image contrast. The correct choice of lighting method, aperture size and lens performance can increase image contrast and improve system performance. Although designers may consider upgrading lighting and lenses in order to increase system performance with high-power laser mirrors, this approach will result in a significant increase in the cost of the system.
But if the designer evaluates the spectral characteristics of the imaged object, they will find that they only need to use different filters to greatly improve the imaging quality at a very low price. At the same time minimize the impact on other design elements.
According to the system structure and spectral transmittance curve, there are a series of filters for designers to choose. The long-wave pass filter is designed to cut short-wave light and transmit long-wave light. The short-wave pass filter is designed to transmit short-wave light and cut off long-wave light. The band-pass filter transmits light of the center wavelength and cuts off long-wave and short-wave light. The notch filter, on the other hand, cuts off light of a certain central wavelength and transmits long mirror wave and short wave light. The application range of each type of filter depends on their manufacturing technology. For example, color filters cannot be used where notch filters are used.
Colored glass filter provides designers with cheap contrast improvement solutions suitable for many applications, but this is only to distinguish objects in a wide spectral range Features, such as distinguishing orange and purple objects.
Interference filters also transmit light in a specific wavelength range, but they are more accurate than colored glass filters. Interference filters can provide precise control at the nanometer level to transmit and block light in different wavelength ranges. Neutral density filters and polarizing filters can also improve performance for specific imaging scenarios. In order to use filters correctly, designers must understand the advantages and limitations of various types of filters.