CN-122016251-A - Spectrum measuring method for segmented mirror surface channel

Abstract

The invention relates to a method for measuring a channel spectrum of a segmented mirror surface, which belongs to the technical field of optical measurement and solves the problems that the existing common-phase detection technology can not meet the detection requirements of high precision, large range, real-time performance and the like at the same time, and the difficulty and complexity of realizing common phase of a main mirror system are further increased along with the increase of the number of spliced sub mirrors. The invention can realize accurate determination of the spectral side of the segmented mirror surface channel, and provides a basis for correction of an active optical system, thereby obtaining the high-precision splice mirror in a global coplanar state.

Inventors

• AN QICHANG
• LIU XINYUE
• LI HONGWEN

Assignees

• 中国科学院长春光学精密机械与物理研究所

Dates

Publication Date

20260512

Application Date

20260212

Claims (3)

1. 1. A method for determining a segmented mirror channel spectrum, comprising the steps of: the optical fiber beam combining device is adopted for the light source input, coherent light with different wavelengths is utilized for beam combination, and the coherent light enters the segmented mirror system in an incident mode; Constructing an interference intensity distribution template of the sub-channel spectrum by utilizing a theoretical model; obtaining the central stripe position of each section of channel spectrum; And combining the dispersion constant and the spectrum center position to obtain the segmented mirror step difference.
2. 2. A segmented mirror channel spectrometry method according to claim 1, wherein the segmented mirror system comprises two cylindrical lenses, a dispersive element, a reticle and a segmented mirror.
3. 3. A segmented mirror channel spectrometry according to claim 1 wherein an optical local high-dimensional edge sensor is used to measure the tilt angle of the segmented mirror, and a beamlets from the gantry is used as feedback to replace the local optical closed loop to replace the local high-dimensional sensor.

Description

Spectrum measuring method for segmented mirror surface channel Technical Field The invention belongs to the technical field of optical measurement, and particularly relates to a method for measuring a sectional mirror surface channel spectrum. Background The high angle resolution optical interference array system (Center for High Angular Resolution Astronomy, CHARA) is the earliest constructed planetary interferometer and consists of six telescopes with a meter aperture. The longest base line can reach 300 meters and cover visible light and near infrared bands. The MARKIII planetary interferometer consists of two telescopes with the baseline of 32 meters and adopts an ABCD method to solve the phase detection problem, and is a principle model machine of a American force precise optical interferometer (Navy Precision Optical Interferometer, NPOI) with six calibers of 0.5 meter. The longest base line of the planetary interferometer formed by the telescope can reach 400 meters. The Keck telescope is composed of two ten-meter-level spliced telescopes, and is interconnected by single-mode light rays to form a 140-meter baseline planetary interferometer. On this basis, by connecting a plurality of telescopes, OHANA (Optical HAWAIIAN ARRAY for Nano-radian Astronomy) interferometric array concepts are proposed. The European southern astronomical very large telescope interference array (VERY LARGE Telescope Interferometer) is composed of four 8.2 m telescopes and four 1.8 m telescopes, can provide a hundred-meter baseline, and can realize light beam synthesis in visible light, near infrared and medium-long wave bands after correcting wave fronts of the base line through self-adaptive optics. The angle of the celestial body can be accurately measured by using long baseline interference. Has high value in extra-train planet detection and interstellar environment detection. The large binoculars interference array is realized by two 8.4 m primary mirrors under a common tracking frame. The longest baseline is 22 meters, and planetary interferometry can be realized in near infrared and mid-infrared bands. The ground-based planetary interferometer can realize detection with higher resolution, but has larger challenges in the light beam collection and synthesis stage due to external environment influence, vibration and other factors. With adaptive optics, the complexity of the system will increase greatly, thus it is proposed to use a space-based system to achieve planetary interference. The united states space interferometry mission planning (SIM-PlanetQuest) will use the visible band to achieve large field of view measurements for six meters of baselines with angular accuracy better than 4 aas at 15 degrees of field of view. The binoculars infrared interferometer project proposed in the united states (The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII)) has a baseline of eight meters, consists of two telescopes of 0.5 meters, combines fourier spectroscopy in the long-wave infrared band, and finally achieves spatial resolution better than 1 angular second. The current high-precision planetary detector faces several significant difficulties. The resolution of the back-end stripes is limited by the resolution of the system pixels, and a longer focal length can greatly increase the volume and weight of the system and is subject to more external disturbance. In the case of lower pixel resolution, higher phase positioning accuracy cannot be obtained. The second problem is that to achieve high contrast imaging, zero elimination interference is required, wavefront phase needs to be rearranged, and when beam refraction is performed by using the bulk optical element, the volume and the actual physics are limited, and the number of measured paths is limited. Astronomical photonics is an emerging subject in recent years, and by means of optical communication and other technologies, the measurement flux and cost performance of a long baseline interferometer are greatly improved, and meanwhile, the volume weight of the system is reduced, so that the system is more suitable for an astronomical interference system. The next generation planetary interferometer adopts an astronomical photonics mode, performs light splitting, aperture rearrangement and interference synthesis through a photonic device, and realizes high-resolution and high-contrast imaging on the basis. For system implementation architecture aspects, the front-end beam-gathering portion will still employ a large aperture telescope for beam gathering. Is coupled into the waveguide after alignment adjustment. The large-caliber segmented space optical system is an advanced scientific load which relates to optics, materials, machinery, control science and other subjects at the same time, and if the spliced mirror surface of the large-caliber segmented space optical system wants to realize the imaging capability same as that of an equivalent single mirror,