The necessary discussion is concerning the indices of laser pointer

The necessary discussion is concerning the indices of laser pointer
NASDA (NASDA) research and development of laser space communications (ILC) system, and plans in the free space station in 1998, the Japanese Experiment Module (JEM) and the Data Relay and Tracking Satellite (DRTS) between ILC system experiments. Another plan is the Laser Communications Engineering Test Satellite (OICETS) program. OICETS plans by Japan and Europe to build a satellite communication link between the synchronous relay satellite launched in 1997 the ARTEMIS in Europe to install a semiconductor laser inter-satellite test device, in OICETS satellite launched in 1998 to install a terminals. By then, the synchronous orbit satellites (GEO) and low-orbit satellites (LEO) device between the laser satellite communications. The quantity and quality of laser pointer have to be guaranteed.
Track (Acquisition, Pointing, Tracking referred to as APT) technology is pretty complex, and this is resulting in the development of satellite optical communication one of the reasons for the slow. 2, there is background light. Background light comes from the sun, moon, Venus, Earth and other The planet's radiation, reflection, radiation intensity of the background light spectrum distribution angle into the receiver when the receiver field of view contains the noise source at the same time, the affected receiver also. 22 Data Relay Satellite technology - laser communications data, background light can sometimes reach the extent of a strong, far greater than the received signal light intensity, which requires communication between the satellite system has a strong anti- background noise. It helps improve the production of laser pointer .
For example, the common layer buried heterostructure (BH) Fabry-the Perlow semiconductor lasers in the number of Gb / s direct modulation. Dynamic spectral broadening can the above 10urn. Therefore, high-speed communication systems require line width is very narrow, high-speed modulation to maintain the so-called dynamic model of a single longitudinal-longitudinal-mode (I) SIJM) semiconductor lasers. As a high-performance semiconductor lasers. The quantum order of the basic structure of the material (especially strained quantum cake) semiconductor laser has a good dynamic characteristics. Many forms of SLM laser, the most effective is the introduction of the dispersive element in the cavity or cavity semiconductor lasers - grating, whose basic principle is the dispersive element is only a specific wavelength selection of the best feedback.