The ground power generation efficiency and the cost is much higher than the space. So in the foreseeable future, the largest diode laser transmission is not transmit energy, but the transmission of information. That is the essence of our study, is how the information returned by energy channels.
Diode laser is pointing to the poor, the radiation loss is too large; the problem is the loss of atmospheric laser, electro-optic / photoelectric conversion efficiency is poor. Of course, on the other hand, pointing to the good reception of the poor, to actually need to good ATP tracking technology development.
The earth does not need so much energy.Diode laser enough. On that day, our energy utilization ability should be strong, that the return of the energy if not big enough, not affect the total amount of energy, or the lack of human resources on earth can be obtained in 5%, there is no need to be so hard.
Short wavelength loss too fast, such as the diode laser. too long not directed, such as FM 83. Seven only microwave to THz is feasible. The feeling is not difficult, get a wide receiver in unmanned area is good. Don’t try to frame the wire or waveguide, it can withstand the power does not stand the loss of several hundred kilometers, is not worth coming back.
The picture mechanism of similar problems in the narrow pulse diode laser. Using ultrahigh peak power and damage to the device, which is mainly the action of heat rarely, photons and substances directly damage the device. The pulse width is shorter, the effect of heat less, for example.
Nanosecond pulsed diode laser can cut steel, but it is difficult to cut crystal, because the action time is too long, can make the crystal crack. Picosecond pulse laser can be cut sapphire, smooth incision, thermal effects, does not damage the gems. Laser can cut the lens and retina of femtosecond pulse, very little heat effect, no damage to other organs.
We can put the diode laser into light, middle school physics tells us that light is a wave like two nature. We assume that a light beam to the mirror, the light is totally reflected light, the momentum is changed, then according to the law of conservation of momentum, the mirror will be a light to it, the the force is called pressure.
So the diode laser hit the water drop, a part of penetration, reflecting a part, there was the picture you sent the case. The high energy laser to produce high temperature melt objects you said is case of penetration, do not know much, not specifically say, before the ultra high-speed camera were successfully recorded when the electric cylinder light into the bottle of water from a water bottle, water bottle shaking a bit, of course, the human eye is not observed.
To improve the conversion efficiency not only can obtain high output power, make the system work in the critical state from injury, but also improve the stability and security of the system. But limited by the pump source diode laser beam quality, pulse width, pulse energy, and the nonlinear crystal quality and parameter conversion process of phase mismatch, inverse conversion factors go off effect of the pulse infrared laser to obtain high conversion efficiency is always a challenge.
As everyone knows, diode laser and the diameter of the pump beam and its power density is closely related, in order to obtain the pump power density is high, the researchers usually have to be less energy pump focused in nonlinear crystal, and the small spot and limit the conversion efficiency, and the focus will cause the nonlinear phase transformation process mismatch. Inverse conversion, walk off effect phenomenon, hindering obtain high conversion efficiency.
Study on the nonlinear diode laser independent growth of ZGP crystal, high damage threshold and high nonlinear coefficient is 3 to 5 microns in infrared band best crystal materials. However, the laser crystal must with a wavelength of 2 micrometers or more, and now the wave period of commercial laser cannot meet the high conversion the efficiency of the demand, cannot obtain a short laser pulse, and pump energy is higher.
The design of diode laser considering the optimal size and power density of the pump beam parameters, optimum length of the nonlinear crystal and the optimum output rate, in which the nonlinear conversion required high peak power density at the same time, the pump beam was optimized to improve its spatial uniformity and reducing the divergence angle.