The member card of laser pointers has a deadline

 The member card of laser pointers has a deadline.
The invention of lasers and optical communication applications for the development of more underwater optical communication has brought the gospel, and therefore has a high data transfer rates, excellent privacy and interference studies of underwater communication of great strategic significance. The United States in a number of potential maritime laser communication test basis, launched a communications satellite on the potential overall feasibility study, plans to use high-power solid-state lasers with only a few hundred kilometers above the ground inexpensive, low-orbit satellites, instead of previous plans to use geostationary satellites to carry out duplex satellite - research submarine laser communication system [7]. Direction of the laser is a strong color performance and is highly concentrated coherent light beam, the use of lenses to focus light into a very small point, the spot on the energy density is very high, and can in a few microseconds or a few milliseconds play a role, by focusing the laser spot after up to tens of microns in diameter, which can be precisely in the treatment of choice lesions .
Information is sent, the first converted into electrical signals, and then by the modulated light modulator to generate the laser beam on the laser, the optical antenna out. Information received, the optical receiving antenna will receive the optical signal is focused, sent to restore the light detector into an electrical signal, in the reduction of information. Atmospheric laser communication capacity, confidentiality, and immune to electromagnetic interference. However, when laser transmission in the atmosphere by rain, fog, snow, frost and other effects of attenuation should be increased, it is generally used for the border, island, across rivers and other short-range communication, and the atmosphere outside the inter-satellite communications and deep space communications. The brief introduction of laser pointers will be sent to the customer.
Early laser light source used in the majority of air traffic for the carbon dioxide laser, helium - neon lasers. Carbon dioxide laser output laser wavelength of 10.6 microns, the wavelength channel just in the atmosphere of low-loss transmission window is an ideal source of communication. From the late 1970s to the mid-1980s, due to the technology difficult to solve the all-weather, high mobility, flexibility, stability and other issues, atmospheric laser communications research at a low ebb. The technical specification of laser pointers is included in the report.
In 1988, Brazil announced the successful development of a portable laser atmospheric communication system. This line of military Unicom by infrared laser communications devices, its appearance as a pair of binoculars, laser diode installed in the above and a microphone. When used, the other party will aim to achieve binoculars communication, communication distance of 1 km, if the optical antenna fixed, the communication distance of up to 15 km.