(1) Laser optical homogeneity of glass - the refractive index error of ± 2 * 10 (-6), while the ordinary refractive index of optical glass homogeneity error is ± 2 * 10 (-4);
(2) 1054nm Department through the loss of less than 0.0015cm (-1);
(3) glass in the OH radicals and platinum were very low;
A size of 500mm * 300mm * 50mm neodymium-doped glass laser cost not less than 20,000 yuan.
Laser glass is a glass as a substrate solid-state laser materials. It is widely used in various types of solid laser device in, and become a high power and high-energy lasers the main laser material. Laser glass and laser crystal compared to the main advantages:
(1) easy to prepare. Application Preparation of optical glass technology and make improvements, access to high level of transparency and optical uniformity of the glass, more easily obtained by the large size end of the work material properties, low cost, large size and with high density of active particles is the number of high power and the importance of favorable conditions for high-energy lasers.
(2) matrix glass is susceptible to changes. Matrix glass composition and nature of changes in range, added the type and quantity of active agent is not very restricted, it is more likely to develop into a variety of unique species series of laser glass.
(3) easy molding processing. Optical glass thermal forming and cold techniques, laser glass molding for a variety of shapes easy to direct, such as rods, sheets, wire, etc., and research into high-precision optical surface density to meet the development needs of a variety of devices structure.
(4) Based on the characteristics of the glass structure, that is short-range order and long-range disorder, structural defects on the broken glass in the glass properties of a small and easy to remove, so easy access to the isotropic, uniform large volume of work on the nature of the material . Neodymium glass laser due to produce at room temperature, the temperature quenching effects are small, light and pump light absorption efficiency of the quantum string is currently the most efficient laser glass.
Laser glass, glass and activated by the matrix ions of two parts. Various physical and chemical properties of laser glass, the major decision by the glass substrate, and its spectral properties are mainly decided by the activated ion. However, glass and activation of matrix ions interact with each other, so the laser activation of ion physical and chemical properties of glass have a certain influence, but its spectral properties of the glass substrate of sometimes very important. As a laser glass substrate glass, optical glass, now mostly, but not any kind of optical glass access any of the active ions are suitable for laser glass.
Laser glass must meet some basic demands:
(1) activation of ion emission institutions must have a metastable state, can form a three-level or four vertical body; and calls metastability a longer life, so that accumulation of particles easy to reverse. In order to have high efficiency laser glass and low-oscillation value terms from the level institutions, four-level better than 3 level. When the final state level with the ground state level energy interval between the time greater than 1000 cm -1, at room temperature, the final state level is almost empty, therefore, at room temperature, the pump also prone to inversion. Currently produced in the glass of various activated ion laser to Nd3 + ion is the best, for the four-level agencies, the final state of laser transition and ground state level spacing of about 1950 cm.
(2) laser glass must have all appropriate string spectrum. Including the nature of the absorption spectrum, called optical excitation radiation source within the broad and more gradual absorption band, a high absorption coefficient, absorption band and the radiation source as possible with the peak overlap, so help make full use of the excitation source energy; fluorescence spectrum, the general requirements of its small and narrow fluorescence bands, so that the output energy would not be dispersed; the same time to absorb the laser energy as much as possible into the laser energy, also called fluorescence quantum efficiency as high as possible , the internal energy loss as small as possible.
(3) Laser glass substrate must have good transparency, in particular the absorption of the laser wavelength should be as low as possible. Transparent glass substrate, can make the optical pump fully activated ion energy is absorbed into a laser. Increase transparency and reduce the matrix on the absorption of optical pump energy, Er Shi laser glass temperature, this will bring a series of shortcomings. At present the majority of optical pump radiation bands in the visible light and near ultraviolet and infrared regions, so you must select a transparent material in the region. In the inorganic oxide and fluoride glass to glass more appropriate. If the glass matrix containing iron, copper, lead, manganese, cobalt, nickel and other transition metals compounds. In the near ultraviolet to the infrared has strong absorption, the transparency of glass substrate will decrease. Laser wavelength in the glass caused the main source of absorbing impurities. Laser glass must have good optical uniformity. Optical inhomogeneity of laser glass to light through the glass surface after the wave deformation and generation of path difference, the oscillation threshold to promote efficiency liang lower divergence angle increases.
(4) laser glass must have good thermal stability and light pieces. Lasers work because activation of ion loss and non-radiative transition matrix glass ultraviolet and infrared part of the pump light absorption of light energy into heat the glass temperature. Meanwhile, due to the different conditions of heat absorption and cooling of the radial bar will appear in the temperature gradient. In addition to these factors led to the optical homogeneity of laser glass, the decrease of laser performance, laser could even be good mechanical properties of glass due to thermal damage.
(5) laser glass must have good physical and chemical properties. In addition to the above points requirements, in order to facilitate manufacturing, processing and use, also called laser glass has a good of special chemical properties. This includes the loss through the tendency of small, high chemical stability. A certain mechanical strength and good light stability and thermal conductivity and so on. Lost through the high tendency of the glass to glass, especially large pieces of glass to bring the production process difficult, and difficult to obtain high optical homogeneity of glass.