green laser pointer also has the functions of a keyboard

green laser pointer also has the functions of a keyboard
Need to work the material can achieve population inversion distribution of excitation energy of - - the pump source. Need direction and frequency can be selected optical resonator. Schematic laser reflection constitutes 100% of the total reflection mirror and the reflection rate of 90% to 95% of the part of the parallel mirrors placed on the ends to form the cavity material. The emitter of green laser pointer applies the ergonomic design.Cavity in the work material under the action of the pump source, in the distribution of population inversion, spontaneous emission of photons due to stimulated emission of radiation continued to enlarge, producing photons in the resonator mirror after multiple reflections in the non-resonant cavity along the axial direction of the cavity photon escape quickly, and back and forth along the axial direction of the photon transmission, constantly being enlarged, and the direction, gain continuous improvement, and finally from the laser mirror. Laser is the laser output in addition to the above three basic conditions must be met to produce the laser threshold condition threshold condition phase conditions and phase conditions of the threshold conditions for the phase condition.The emitter of green laser pointer is suited to work for a long time. In the course of laser operation, the light propagation in a resonant cavity, in addition to the optical gain medium in addition to amplification, there are also the work of the absorption of the material, the optical amplification gain medium, but also the absorption of the material existence of the work, the medium caused by uneven scattering, the scattering medium caused by the uneven, non-ideal nature of the mirror transmission and scattering caused by wear and tear, so it was only light transmission and scattering in the resonance cavity loss of the amplification gain is greater than a reciprocating wear and tear caused by a variety of attenuation of the laser in order to establish a stable laser output, the threshold of the threshold condition (critical condition) is 1 r1 γ th = α + ln 2 L r2 γth stable laser output for the minimum necessary to gain, known as the threshold value of the gain coefficient; α resonant cavity for the work material loss factor; L the cavity length for the resonant cavity; r1, r2 for the two mirror reflectivity. The emitter of green laser pointer is designed for working for a long time.As in the cavity, the light is transmitted back and forth between two mirrors, and then only if they meet specific phase relationship of light to be mutually reinforcing, so this condition is called phase condition phase conditions, namely: the phase condition cq fq = 2nL where, fq is the frequency of light waves; n is the refractive index of the working medium; c is the speed of light; q = 1,2, .... It can be seen from the above equation, the laser light laser oscillation in the oscillation frequency of the light can only take certain discrete values, a series of different values of q corresponds to the frequency can only take certain discrete values, corresponding to different values along the series resonant axial cavity electromagnetic field distribution of a range of different, along the cavity axis electromagnetic field distribution of a range of different, a distribution is a longitudinal mode laser longitudinal modes.