Laser far field divergence angle measurement method and device in satellite laser ranging

Abstract

The invention relates to a laser far field divergence angle measurement method and device in satellite laser ranging, and belongs to the field of optical technologies. The device comprises a laser emitting system, a spot imaging system and an image processing system. The laser emitting system comprises a laser, a laser beam expanding optical path, a telescope and a hole limiting plate. The laser beam expanding optical path is composed of a negative lens and a positive lens. The spot imaging system comprises a ground glass screen, an imaging lens set and a high-resolution CMOS camera. The image processing system comprises an image acquisition card, an image processing module and a data processing module. According to the invention, compared with a traditional method, the laser far field laser divergence angle measurement device is more accurate and reliable, solves difficulties of large diameter laser beam divergence angle measurement, uses less equipment to complete the measurement, and has the advantages of being simple, cost saving and easy promotion and application.

Description

technical field [0001] The invention belongs to the field of optical technology, and in particular relates to a method and a device for measuring a laser far-field divergence angle, in particular to a method and a device for measuring a laser divergence angle in a satellite laser ranging system. Background technique [0002] Laser far-field divergence angle is an important parameter of laser quality, which can reflect the divergence characteristics of long-distance transmission. As laser technology is increasingly widely used in many fields of the national economy, such as laser communication, laser radar, laser ranging and space optical communication, etc., the far-field divergence angle of the laser beam is required to be small. The reduction of the divergence angle of the laser beam can effectively use the laser energy, make the beam have good directionality and high brightness, reduce the requirements on the system's transmission power and receiving sensitivity, and incr...

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Problems solved by technology

The existing laser far-field divergence angle measurement methods mainly include: (1) pinhole scanning method, which measures the profile distribution of the light intensity of the beam, but this method requires that the scanned pinhole must pass through the center of the spot, otherwise it will cause large errors , in addition, if the spot to be measured is small, the required pinhole will be smaller, which will increase the difficulty of measurement; (2) the aperture method is more convenient to operate, but it is difficult to measure the tiny laser beam at the focal point after the lens is focused. (3) The slit scanning method, which measures the light intensity distribution of Gaussian beams, is more convenient than the pinhole scanning method and saves the trouble of centering, but there is a large error in the measurement, and the measurement of the small spot The measurement is powerless; (4) focus knife-edge method, the laser beam divergence angle is measured by measuring the energy integral distribution diagram of the spot, this method is not affected by the laser intensity and the position of the beam waist, a chopper is inserted in the optical path, and by measuring The laser beam energy of each time period is used to measure the divergence angle of the continuous laser, but this method has

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