Light is actually an electromagnetic wave, light waves are only a small part of the entire electromagnetic spectrum, and the wavelength range of visible light is between 380-780nm. There is also invisible light. For example, ultraviolet and infrared. There are also electromagnetic waves, such as rays. Various waves, such as X-rays, account for the majority of electromagnetic waves. There are other electromagnetic waves, such as electromagnetic waves that transmit signals, televisions, and so on. At present, people are also developing and improving the use of visible light waves to transmit data signals, which is called visible light communication. This kind of communication has the characteristics of height, large capacity, security and energy saving. The energy consumption is much lower than that of 5G and 6G, and it has a relatively broad development prospect, for example, the total transmission rate of multi-color Led light source can reach 15Gbps, and the integration of lighting, display and communication is also very space and prospect.

Let's get back to light, which can actually be defined mathematically, that is, by various definitions and related parameters. Common relevant parameters include luminous flux, luminous intensity, illuminance, brightness, color temperature, and more.

First of all, we can understand the wavelength of light

1-380nm is ultraviolet light, while 1-280nm is far ultraviolet, 280-315 is medium ultraviolet, and 315-380 is near ultraviolet, and they have different practical uses. Ultraviolet light is usually represented by UV in English

380-435nm violet light

435-500nm blue light, cyanogram

500nm-566nm green light

566-600nm yellow light

600-630nm orange light

630nm-780nm is red light

780-1000000nm is infrared, of which 780-1400nm is near-infrared, 1400-3000nm is mid-infrared, and 3000-1000000nm is far-infrared, and infrared is usually represented by English IR

Here you can talk about white light first, LED white light is usually through the blue-green chip to excite yellow phosphors to produce white light, and due to the principle of this white light generation, there may be too much blue light in LED lighting, in the spectrum diagram, the peak of visible blue light is relatively high, and blue light for people, too much blue light will form a certain harm. For example, the influence of the retina, the influence of the person's circadian rhythm, the influence of the person's sleep, and so on. Therefore, in line with the principle of insurance, the standard now requires that the lighting color temperature of LED light source should not exceed 4000k for a long time, so as to avoid the harm that may be caused by too much blue light to a large extent, of course, with the progress of white light technology and the progress of related optical design, this excessive blue light hazard will be smaller and smaller, and there will not even be the so-called blue light hazard. Moreover, as long as the lighting products meet the requirements of the anti-blue light level, they can also be used with confidence.

Light wave characteristics

The transmission speed of various electromagnetic waves is about the same. Including light waves, the speed in a vacuum is about 3 x 10 to the 8th power per second, but there is a medium in the air, so the wavelength and speed will change. The frequency of the light wave has nothing to do with the medium, but has to do with the light source of the light wave, and these core elements form various forms of light.

The wavelength of light is expressed in nm.

When light travels in the same medium, the route is straight, but if the medium changes, the light will form reflection, refraction and other phenomena, and the shape of the light will change, which provides space for optical design.

We can take a look at several common parameters for measuring light, which we often encounter when we look at lighting-related materials or buy lamps, or understand the knowledge of related light. These parameters allow us to understand light from the data. Understanding what these parameters mean can lead to a better understanding of light and some optical illumination designs.

Common examples of these parameters include:

Luminous flux, illuminance, luminous intensity, brightness, color temperature, color rendering and luminous efficiency, etc. There are also some parameters that are less common, such as light emittance, and so on. These units of light measurement are correlated. For example, there is a conversion relationship between luminous flux, light intensity and illuminance.