The technology confirmation meeting of laser pointer

 The technology confirmation meeting of laser pointer will be held as required by the customer.
ZEMAX software simulation based on the focal length and aberration curve results, I finally selected 25.8577mm the focal length, thus ensuring the minimum aberration. Through software emulation operations, before and after the collimating lens and the surface of the radius were 18.472mm-84.835mm. Thickness of 7mm, diameter of 10mm. This makes the divergence angle of compression to the 0.04267mrad, even if the distance is only a 500m radius of 21.34mm size of the circular spot, usually less than the full radius of 50mm target surface. This will not only meet the requirements of the laser range finder, but also saves manufacturing costs and facilitate the realization of small, modular, to ensure sufficient received power. The parents are informed of the fact that the school will be equipped with laser pointer .
Similarly the use of ZEMAX software, I designed a 10mm focal length of receiving lens. Lens thickness is 4mm, the front surface radius of 7.831mm, the surface radius-42.824mm. Because the receiving waves not only with the output of 635nm wavelength red light, also contains other miscellaneous light, so I further analysis of the receiver lens chromatic aberration, to ensure the output of 635nm wave normal reception. Since the receiver does not require a high use of the lens, so the receiving system needs further filtering and error analysis. Study, produced in Germany ACAM TDC-GP2 chip, the system averaged multiple measurements, and then calculating the average of the microcontroller to reduce the output error results. The company pays more attention to manufacture of laser pointer due to the large quantity of laser pointer . 
Since the voltage generated by circuit supply voltage, temperature and other factors, so in order to produce high-pressure stability, and high-pressure adjustable within a certain range, the high-voltage circuit to add a feedback loop, as shown: test distance, due to different measuring the distance, leading to APD driver circuit output voltage signal changes drastically. In order to get a smaller signal amplitude changes in the preamplifier circuit, selection of automatic gain control (AGC) function of the amplifier, as shown in Figure. Preamplifier output signal amplitude, signal to noise ratio measurement unit is not enough to meet the requirements. In order to obtain sufficient signal to noise ratio and a higher magnification, the subsequent signal processing also need to zoom in and shaping.Among them, the non-axial propagation of light waves outside the cavity escapes soon: axial propagation of light waves able to spread in the cavity round-trip, when it spread in the laser material, the light intensity is growing.