Coronagraph scattered stray light testing device and testing method

Abstract

The invention provides a stray light testing device and a stray light testing method for a coronagraph. The testing device comprises a laser, a first optical fiber coupler, a polarization maintaining optical fiber, an optical fiber circulator, a beam expander, a second optical fiber coupler, a spectroscope, an oscilloscope and the like. An incident light path and a feedback light path are constructed through the optical components. Based on information such as light intensity and amplitude of an incident light path and a feedback light path, stray light detection of the coronagraph can be completed. The specific method comprises a coronagraph scattered stray light testing method and an outer blindage diffracted light testing method. When the total stray light test of the coronagraph is carried out, the second optical fiber coupler is arranged at the position of a coronagraph detector; when an outer shield edge diffraction light test is carried out, the second optical fiber coupler is arranged at the position of an inner shield of the coronagraph; the stray light level of the coronagraph is determined according to the measurement result of the oscilloscope. According to the device and the method, high-sensitivity detection of weak stray light signals of different sources of the external coronagraph can be realized.

Description

technical field [0001] The invention relates to the technical field of space optical detection, and specifically designs a coronagraph stray light testing device and a testing method. Background technique [0002] The corona is the outermost layer of the solar atmosphere, and it is also the place where many solar physical phenomena occur. Various material transport and energy transmission activities significantly affect the solar-terrestrial space environment and near-Earth space weather. Observing the corona is extremely important for in-depth understanding of scientific issues such as solar activity, as well as practical issues such as forecasting space weather. But because the density of the corona is very low, compared with the photosphere luminescence in the central region of the sun, the energy density of the radiation is also very weak, and the farther away from the sun, the brightness of the corona will decrease rapidly. Therefore, the corona cannot be directly obse...

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Problems solved by technology

But there are deficiencies: First, for the field of view tens of R ⊙ The stray light level of the external field of view during the ground test is lower than 10-11B ⊙ This requires an extremely bright light source, otherwise the integration time of the detector is too long and non-stray light signals such as electronic noise are mixed, but a high-brightness light source is difficult to achieve, especially to output a uniform parallel beam and to be tested When the coronagraph has a large aperture; secondly, the stray light test using the detector CCD or CMOS needs to cooperate with the imaging lens or the coronagraph optical system. The stray light of the aperture and so on is mixed together, and it is impossible to conduct separate tests to quantitatively analyze the influence of the shading parts and optical elements such as the outer shelter on the total stray light; finally, because the coronagraph test environment cannot be an infinite space that is completely non-reflective , even if a single-pixel detector with higher sensitivity is used to test stray light, the reflected / scattered light formed by surrounding objects illuminated by a strong light source will enter the coronagraph again to form ambient light noise, so that the test for weak stray light cannot meet the design Level

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