Light Scattering Particle Counter Sensor Photosensitive Area Of The Beam Shaping Design

Laser airborne particle counter (LAPC) is designed to measure the number and si ze of airborne particles for the evaluation of air cleanliness and food, medical, cosmet ics cleanliness, and it is the modern high-tech product. Laser airborne particle counter measures the particle’s size to the absolute strength of the particle of the scattering li ght signal. It is the key for the same size of the particles producing the same amplitu de of the light scattering signal. Then we can ensure that the laser particlecounter has a better ability of resolution. So the optical sensor is an important part of the instru ment. This paper designs an aspheric beam shaping system which is used for light sc attering particle counting sensor photosensitive area. The area has good Light intensity distribution uniformity which certifies the resolution capability of particl e size.Requirements of photosensitive area are determined by the material research on th e basis of production practice, length×width×height:7mm×1.5mm×1mm,and its unifor mity is more than85%. On this basis, the design of beam shaping system is establish ed. The spherical of the seidel aberration transformed into the aspherical of theseidel a berration. More optimized initial structure parameters are decided by using optical path principle such as PW.In the sequence mode of Zemax optical software, surface light source model of s emiconductor laser, the initial structure light path model and the evaluation functionon basis of the index of photosensitive area are established. The parametric optimal desi gn is made for beam shaping system. And the performance index of optical system is analyzed. Testing the photosensitive area in Zemax non-sequential mode, the size of t he spot is7mm×3mm×0.8mm. The simulation results show that it meets therequireme nt of design. The final,analysis the tolerance of the optical system to givethe reasona ble tolerances. Use solidworks mechanical software design the assembly parts of the le ns with the CAXA drawn diagram of optical parts, optical system diagram, system ass embly drawing.