green laser pointer is most mature in the laser technology

green laser pointer  is to remotely control and play the PPT document and so on.
It will automatically dial, busy tone recognition, tone recognition, remote access key digital signal recognition. We choose MT8888 dual-tone multi frequency (DTMF) transceiver, and single-chip audio amplifier portfolio, to achieve a variety of tone detection and generation of DTMF signals, and the DTMF signal to the telephone line, shown in Figure 3. MT8888 is a DTMF signal using CMOS technology, the transceiver IC. Part of it to send the signal distortion, high frequency stability of switched-capacitor D / A converter can be issued 16 kinds of dual-tone multi-frequency DTMF signal. The receiving part is used to complete the makeup of the DTMF signals received, separation and decoding, and four parallel binary code output. Maltreat of  green laser pointer  might be complained or even punished. Therefore,  green laser pointer is most mature in the laser technology
Of Er: glass laser rangefinder After years of research and practice, has now developed a variety of handheld or car with the rangefinder, such as the United States, LB-7, France HH-7. Its disadvantages are: closed-valued, low output energy, short life; Er: glass materials production difficulties; and limited by the low thermal conductivity of the matrix glass material, the laser repetition frequency is low, not suitable for high repetition rate applications (such as air defense, etc.); has not yet applicable to passive dye Q-switched. Raman frequency shift of the Nd: YAG laser. Raman frequency shift of Nd: YAG laser is a Nd: YAG laser into the high pressure methane gas box (or neon gas Raman medium), stimulated Raman scattering, the 1.06μm wavelength of the laser frequency to move to 1.54μm. The customer can not just use green laser pointer  without considering any others.
Semiconductor laser rangefinder has a simple structure, small size, light weight, low-cost, high repetition rate, high efficiency, short-ranging, there are obvious advantages, but the output power is too low, the receiving system error is too large issues such as greatly limits ranging applications. So how to improve the performance of the laser range finder is one of the problems to be solved. In this paper, single-lens collimator system for the compression of the divergence angle so as to improve the purpose of transmitting power. 635nm laser diode light source, using the ZEMAX software to simulate the imaging aberrations of the lens collimator system, select the best design. For short-range pulsed laser ranging error. In all, the customer should pay much attention to the use and safety of green laser pointer .