Furthermore, excimer lasers, free electron lasers, chemical lasers, fiber lasers and other laser devices of the new development and a better prospect. This section is only for a brief introduction of these lasers. Excimer laser. Under normal conditions, atoms can temporarily combine into unstable molecules in the excited state, called excimer, referred to as the excimer. The substance of the work of the excimer laser is the excimer gas. Since the advent of the first excimer laser in 1970, it successfully developed a variety of excimer lasers in isotope separation, photochemistry, pumped dye lasers has made a contribution. In the development of laser weapons, it is also one of the very promising laser. This high power laser pointer is the good tool and assistant for the customer.
Excimer laser treatment of myopia has also achieved good economic and social benefits. To date, the excimer laser is more and more, the incentives also continue to improve power and increased efficiency. Pulse energy has reached the order of one hundred joules, pulse peak power of kilowatts or more, the repetition rate of 200 times / sec, the beam divergence angle 0.15mrad. The excimer laser is characterized by distinctive features: the level structure. Figure (5-33) shown in A indicates a higher excited state, B the upper level, C is the ground state. Ground level of the lower laser level. As the ground state to the exclusion of state or weakly bound state is very unstable, it moves along the potential curve C to the nuclear separation R increases fast in the direction until eventually dissociate into atoms. Here is the design and technology of high power laser pointer.
The ground state molecule will disappear. The ground state molecules of life is very short, 10-13s order of magnitude. Excitation state of the bound state, the level lifetime of 10-8s order of magnitude, than the ground state stability in the internuclear distance R0 is very easy to form B, C, between the inversion distribution. The excimer The level structure. Excimer from the excited state to ground state transition from the bound state transition to the free state (weakly bound state or repulsive). Such terminated reversal transition, the approximation of the lower level is empty, so there is no low energy level is filled. Means that the excimer transition is not self-terminate "transition. – The number of excimer reversal there, it is easy to accumulate a considerable amount of particle number, and likely to get larger the population inversion and a larger gain. It will determine which process and production method of high power laser pointer.
The ground state lifetime is very short, even ultrashort pulse case, the ground state can also be considered to be empty, so the excimer system is particularly beneficial to produce the giant pulse. Laser level is the ground state, with virtually no radiation loss. Therefore, a high quantum efficiency, which is the main reason for the excimer laser may reach a high efficiency. Rapid dissociation ion laser level, and thus lengthen the pulse width and high repetition rate are not difficult. Excimer fluorescence spectroscopy with a continuous, it can be made of the frequency tunable devices. Laser level lifetime is very short, in order to achieve population inversion, the pump pulse rise time is short. Therefore, for work in the short wavelength UV laser, excimer system to achieve an effective pump. And manufacturing process of high power laser pointer is used.
Not only requires a large pump power, and requires a fast rise time. In order to meet the requirements of the pump source to take a lot of pump way, commonly used in the following two types: electron-beam pump. Electron gun to produce high-energy, fast rise time of the electron beam pulse, the electron beam fired excimer District, to stimulate the active medium. E-beam pump can be divided into three forms: (1) horizontal pump, the electron beam direction and the laser optical axis is vertical. In this way a simple structure, small size, the drawback is the low use of electron beam energy. ② pumped, the electron beam direction parallel to the laser optical axis. Pumped energy efficiency to be improved, but the need to increase the used electron beam oriented huge bunching field. Here will introduce a very short and small type high power laser pointer.