Search

A experimental method measuring laser energy and energy distributing of large-aperture beam is presented. The experimental equipment is established. The energy and energy distribution of beam, the beam size is Φ100mm and Φ360mm, are measured. The result show measuring error for laser energy is less than 8%. The energy distribution is basically consistent.

A new type of direct transmission visibility measuring device is developed. The device can obtain the visibility by measuring the atmosphere transmittance ratio of laser beam in sampling space. The measuring principle and the design scheme of the device are described. The measuring comparison experiments of this device and the reference transmittance meter are carried out. The experiment results verify the correction of test theory and technique scheme. The relative measurement error is under 20% within the test range of 10 km.

This paper is focus on analyzing the telescopes used in atmosphere, which studies the effect of optical aberration of telescopes to the laser radar. The method of numerical simulation is used to calculate and analyze the characters of backward wave when laser beam propagates through atmosphere and reflects back. Then make use of optical transfer function including quartic phase aberrations to get the beam quality denoting the laser beam pass through the telescopes system with aberration. It takes advantage of angle-of-arrival fluctuations, radius of power in bucket, and scintillation to study the effect of wavefront errors to laser radar. Furthermore, comparing the scintillation of backward wave by diverse intensity of atmospheric turbulence, it discusses the effect of optical aberration to the accuracy of radar. By synthetically numerical analyses, this paper concludes the quantificational effect of different aberration of telescopes to the signal of radar. The conclusion of this paper can be used to direct the design and manufacture of telescopes of optical radar.

A new application of Hartmann-Shack sensor is introduced to measure the beam waist from the information of measured intensity and phase profile of wavefront. The result is achieved by Fresnel-Kirchhoff diffraction theory with proper numerical approximate algorithm. In this paper, the algorithm is applying to the circumstance of long distance propagation. For this specialty, a simulation process in the case of a Gaussian distributed beam and a thin lens of focal length 100m is presented. And the results show the possibility of this method and the degree the result is affected because of the inevitable error introduced in the measurement.