Fabrication of collimating module and measurement of far field divergence of laser beam of 1 550 nm

Theory analysis of the collimation about Gaussian light beam is described and the designed collimating lens have achieved the technique target in wavefront aberration by intervention measurement. The experimental data are measured by the designed experimental installation system and are processed by Gaussian power distributing curve, the spot size corresponding to half of the maximum light power is measured by the light power meter, which is used to determine the far field divergence angle of laser beam. In the experiment, average of the measured maximal light power is 27.89 nW and average of the spot size difference is 6.33 mm. Therefore, minimal far-field divergence angle of the laser beam is 0.315 mrad. The collimation system of the experiment is validated and it can reduce far field di