It depends on the specific indices and parameters

It depends on the specific indices and parameters of green laser pointer . 
In good condition, the focal length of Fourier lens, set the photodetector the first half-ring inner diameter, outer diameter, then the corresponding scattering angle range, to meet the following formula. Figure 2-4 Cartesian coordinate system under the schematic diagram of the situation, where O is the origin. Set up a multi-photodetector located in the XY plane, the geometric center of the detector each ring coincide with the coordinate origin O, the incident light axis QV coincide with the Z-axis. Ideally, as shown in Figure 2-4 (a) below, the second is the geometric center of each ring of the photodetector and the incident light axis do not coincide (eccentric). When the incident oblique, as shown in Figure 2-4 (b) below, the incident light axis of the QV through the center of the multi-photodetector. Or we can say the laser energy of the infrared light band of green laser pointer is less concentrated. 
Optical structure based on light scattering theory and instrumentation, computer prior to calculate the scattering light distribution of various diameters in the range of instruments to measure particle corresponding to the collection composed of a light matrix M, namely: matrix each column represents a grain The diameter of the scope of a unit weight of particles scattering light distribution. Thus: where w1, w2, ..., wn representative particle weight distribution. According to the above equation, as long as the known scattering light distribution s1, s2, ... sn, through appropriate means of numerical calculation can calculate the corresponding particle size distribution. Laser alignment technology. Laser technology on the product of the combination of laser, light sensors and computer testing techniques, efficient, stable and fast. The infrared optical filter of green laser pointer is needed for the customer.Here is the 2000mW blue green laser pointer and so on.Receiver area increases rapidly as the receive angle increases, this time in the vicinity of 14 ° (a particle refractive index of 1.54, the position corresponding to the peak of 1μm particles scattering the light distribution), the light can ambitious predictions theory Fraunhoff. Therefore, if the acceptance angle of the laser particle size analyzer close to or greater than 14 °, or the minimum laser particle size analyzer measurement is less than or equal to 1μm, the diffraction theory obvious error (1μm near the number of particles). The subject laser particle size analyzer using rigorous Mie theory as a theoretical basis.