Blue-green laser refers to short-wave visible light with a wavelength of 0.47 ~ 0.54 microns. This is an effective band for underwater television, communications and lighting. The development of blue-green laser, on the one hand, it is necessary to develop high-efficiency, chemically stable nonlinear frequency doubling crystals, with Nd:YAG or Nd:YAP frequency doubling work, on the other hand, it is hoped to find a direct production of blue-green laser working material. These two aspects, especially the latter in recent years is the domestic and foreign attention to scientific research projects. How to modulate blue-green laser? The 0.48 micron blue-green laser transition has several activation ions to choose from, Such as Pr ~ (3 +) ~ 3 Po - > ~ 3 h_4 and Tb ~ (3 +) ~ d_4 - > 5 ~ 7 f_6, Dy ~ (3 +) ~ 4 f_ (9/2) - > ~ 6 h_ (15) / 2, Er ~ (3 +) 2 ~ p_ (3/2) - > ~ 4 i_ (1) ~ (3 +) and Tm ~ g_4 - > 1 ~ 3 h_6, etc.
It has taken a decade to develop several small blue-green solid-state lasers, but many observers believe that progress seems to be too slow. The main market for small solid-state blue-green lasers is optical data storage and laser printing, initially for optical disc manufacturing and high-speed printing, and later for high-volume data storage and printing.
What is the standard wavelength of a blue-green laser?
The wavelength of the blue-green laser refers to the output wavelength of the laser, which is an important parameter of the laser output laser beam. The corresponding output frequency is called the laser frequency.
In fact, laser is also a kind of electromagnetic wave, but the wavelength of laser and radio waves is not an order of magnitude, it is many orders of magnitude shorter than radio waves. The wavelength unit of the laser is usually measured by nm (1/1000000000 m), and the laser can be divided into two categories: visible laser and invisible laser. Under normal circumstances, the visible light wavelength that the human eye can clearly distinguish is basically between 400 nm and 700 nm. The shorter the wavelength of the laser, the bluer and purplish its color, until the ultraviolet light is invisible to the human eye. However, the longer the wavelength, the more its color skews toward red, up to infrared, which is invisible to the human eye. The human eye is most sensitive to green, orange and yellow light with wavelengths between 550-570 nanometers. Therefore, in the visible light range, wavelengths can be understood as digital identifiers of colors.
The color wavelength of the visible laser beam from short to long is: blue-violet (375nm, 405nm), blue (445nm, 488nm), green (520nm, 532nm), yellow (589nm,577nm) and red (635nm, 650nm). Lasers in this wavelength range are often used in the field of stage performance and medicine.
From another point of view, it can be said that the propagation of light in vacuum is also through some medium, but this medium has a very special property, the standard wavelength of the blue-green laser it moves at zero speed relative to all inertial reference frames. It is this feature that makes "the speed of light is independent of the speed of the light source" equivalent to "the speed of light is independent of the speed of the observer." The transmission media of sound waves (air, water, etc.) do not have this "forever static" property, so there is no "principle of constant sound speed", and relativity can not be derived from it. In addition, light waves can also propagate in non-vacuum media (such as glass, etc.), but these media do not have this "forever static" property, so the speed of light waves in such media can not be used to replace the speed of light in relativity.
Extended information:
The standard wavelength of blue-green laser is widely used, including laser marking, laser welding, laser cutting, fiber optic communication, laser ranging, laser radar, laser weapons, laser disc, laser correction, laser beauty, laser scanning, laser mosquito killer, LIF non-destructive testing technology and so on. Laser system can be divided into continuous wave laser and pulse laser.
Blue-green laser laser level function:
1. the laser level can measure whether the plane is uneven.
2. laser level can output laser vertical and horizontal points.
3. there are horizontal beads on the laser level, used to measure whether the level is level.
4. there are led lights on the laser level, even at night can see the horizontal beads.