DOI: 10.17586/1023-5086-2019-86-10-39-47

The diffraction-limited Littrow imaging grating spectrometer for the new vacuum solar telescope

Publication in Journal of Optical Technology

For Russian citation (Opticheskii Zhurnal):

Lianhui Zheng, Yun Xie The diffraction-limited Littrow imaging grating spectrometer for the new vacuum solar telescope (Изображающий решёточный спектрометр Литтрова с дифракционным качеством для нового вакуумного солнечного телескопа) [на англ. яз.] // Оптический журнал. 2019. Т. 86. № 10. С. 39–47. http://doi.org/10.17586/1023-5086-2019-86-10-39-47

Lianhui Zheng, Yun Xie The diffraction-limited Littrow imaging grating spectrometer for the new vacuum solar telescope (Изображающий решёточный спектрометр Литтрова с дифракционным качеством для нового вакуумного солнечного телескопа) [in English] // Opticheskii Zhurnal. 2019. V. 86. № 10. P. 39–47. http://doi.org/10.17586/1023-5086-2019-86-10-39-47

For citation (Journal of Optical Technology):

Lianhui Zheng and Yun Xie, "Diffraction-limited Littrow imaging grating spectrometer for the New Vacuum Solar Telescope," Journal of Optical Technology. 86(10), 634-641 (2019). https://doi.org/10.1364/JOT.86.000634

Abstract:

To observe fine structures on the Sun and study thermodynamic properties of the solar atmosphere with different height distribution, the diffraction-limited imaging grating spectrometer with high spectral resolution presents an essential tool. However its imaging performance will be limited by wavefront aberration caused by an atmospheric turbulence, and a static wavefront aberration. In order to compensate the aberrations and lower the manufacturing precision of the optical element, an aberration correction method for a diffractionlimited Littrow imaging grating spectrometer (DLIGS) based on Adaptive Optics is proposed. To correctly detect the static aberration, the calibration system is adopted. To validate the method, the prototype for the new vacuum solar telescope is developed. The results demonstrate that the proposed method is feasible, and the near diffraction-limited imaging performance is achieved after the Adaptive Optics correction. The real spectral resolution of the prototype roughly is 6 pm, which is close to the numerical result (5.6 pm).

Keywords:

solar atmosphere, aberration, adaptive optics, imaging grating spectrometer, spectral resolution

Acknowledgements:

This work is funded by the National Natural Science Foundation of China (No.11178004, 11803015), and the Principal Investigator of Fujian Provincial Department of Science and Technology (2018J05009), Training plan for outstanding young scientists in Colleges and universities in Fujian, Doctoral Research Fund (16YG09), Provincial Health Department Project (2017-1-92). A special acknowledgement is to Prof. Changhui Rao from the Institute of Optics and Electronics, Chinese Academy of Sciences, for his revision we benefited greatly. Meanwhile, we are very grateful to the reviewers for their valuable advice.

OCIS codes: 010.1290, 220.1000, 220.1080, 300.6320

References:

1. Schrijver C.J., Title A.M., Harvey K.L. et al. Large-scale coronal heating by the small-scale magnetic field of the Sun // Nature. 1998. V. 394(6689). P. 152–154.

2. Fisk L.A., Schwadron N.A. The behavior of the open magnetic field of the Sun // The Astrophysical Journal. 2001. V. 560(1). P. 425–438.
3. Ivanov E.V., Obridko V.N. The role of the solar magnetic field systems in modulating the solar irradiance // Advances in Space Research. 2002. V. 29(12). P. 1951–1956.
4. Abbett W.P. The magnetic connection between the convection zone and corona in the quiet Sun // The Astrophysical Journal. 2007. V. 665(2). P. 1469–1488.
5. Bale S.D., Kasper J.C., Howes G.G. et al. Magnetic fluctuation power near proton temperature anisotropy instability thresholds in the solar wind // Physical review letters. 2009. V. 103(21). P. 211101.
6. Volkmer R., O. von der Lühe, Denker C. et al. GREGOR solar telescope: Design and status // Astronomische Nachrichten. 2010. V. 331(6). P. 624–627.
7. Chae J., Park H.M., Ahn K. et al. Fast imaging solar spectrograph of the 1.6 meter new solar telescope at big bear solar observatory // Solar Physics. 2013. V. 288(1). P. 1–22.
8. Rao C.H., Jiang W.H., Ning L. et al. A tilt-correction adaptive optical system for the Solar Telescope of Nanjing University // Chinese Journal of Astronomy and Astrophysics. 2003. V. 3(6). P. 576–586.
9. Rao C.H., Zhu L., Gu N.T. et al. 37-element solar adaptive optics for 26-cm solar fine structure telescope at Yunnan Astronomical Observatory // CHINESE OPTICS LETTERS. 2010. V. 8(10). P. 966–968.
10. Rao C.H., Zhu L., Gu N.T. et al. Solar adaptive optics system for 1-m new vacuum solar telescope // Third AO4ELT Conference-Adaptive Optics for Extremely Large Telescopes. 2013. P. 13295.
11. Zheng L.H., Gu N.T., Rao C.H. et al. The study of the aberration correction method of the solar grating spectrometer based on the Adaptive Optics // Acta Optica Sinica. 2015. V. 30(5). P. 1487–1491.
12. Palmer C.A., Loewen E.G. Diffraction grating handbook. Springfield, OH: Newport Corporation, 2005. 35 p.
13. Liu Z., Xu J., Gu B.Z. New vacuum solar telescope and observations with high resolution // Research in Astronomy & Astrophysics. 2014. V. 14(6). P. 705–718.
14. Shafer A.B., Megill L.R., Droppleman L.A. Optimization of the Czerny–Turner spectrometer // Journal of the Optical Society of America. 1964. V. 54(7). P. 879–886.
15. Chen Q.F., Li Y.C., Ma Z. et al. Surface error compensation of off-axis parabolic mirrors by alignment // Acta Photonica Sinica. 2010. V. 39(9). P. 1578–1581.
16. Born M., Wolf E. Principles of optics. Cambridge, UK: Cambridge University Press, October 1999. P. 203–232.