It is concerning about the star gazing with Laser Pointer

It is concerning about the star gazing with Laser Pointer .
The small size of the semiconductor laser, light weight, low cost, wavelength selectable, and its application throughout the clinical, manufacturing, military, particularly among the most outstanding progress made by the high-power semiconductor laser semiconductor laser works. Laser to produce the principle of the semiconductor laser is a coherent radiation source, to make it generate the laser, you must have three basic conditions: gain conditions: to establish the carrier's reversal of the lasing medium distribution in the semiconductor represent the electron energy is close to a series of continuous level of the band to achieve population inversion in a semiconductor, between the two zone, at the end of the high-energy state of the conduction band the number of electrons in the lower state price with the top of the hole number.
Static applications, the main requirements of the tunable laser is the price, output power and spectral characteristics, that is quite fixed wavelength laser linewidth and stability and it replaced. Wavelength tuning range the greater the cost the better, not how fast the regulation speed. With more and more precision tunable laser for DWDM systems. In dynamic applications, wavelength tunable lasers can work regularly change, to enhance the flexibility of optical networks. Such applications are generally required to provide dynamic wavelength to one wavelength from a network segment or proposed to adapt to the changing capacity requirements. Other applications include reconfigurable optical changes in the multiplexer and optical cross connect in the wavelength converter. laser pointer can be used in different locations practically and efficiently.
As spare parts in order to save costs: tunable lasers can reduce the number of used to support the system in all the different wavelengths of the line cards required. One-time configuration: tunable lasers as both the main transmitter to do the backup transmitter, known as a one-time configuration, this is because its wavelength setting will not change. Most of the filters and other WDM is a specific wavelength. Therefore, it is not at liberty to change the wavelength. The customer wanna a specific pattern style of laser pointer .
Dynamic configuration: Systems Division was put into use, the wavelength of the tunable transmitter can be changed. For example: To meet the requirements of the wavelength of a new customer's network equipment and to change the wavelength of the transmitter.