Recently, the astrophotonics team of NIAOT has made new progress in the research of a VIPA prototype spectrograph with ultra-high resolution and wavelength calibration.

A Virtually Imaged Phased Array (VIPA) as the main dispersion element and laser frequency comb as wavelength calibration source is used by the team, which can realise spectral resolution of 1.06 million with short –term wavelength calibration accuracy better than 10 cm/s.

6-hour two-channel synchronous wavelength calibration accuracy can only reach ~13 m/s and parity calibration accuracy ~40 cm/s because of influence of temperature and pressure on the instrument.

The results were published in the International Astronomical Journal called “The Astronomical Journal” on August 26 (https://doi.org/10.3847/1538-3881/aba836).

According to introduction given by Dr. Zhu Xiaoming and Prof. He Jinping (Xiaoming Zhu https://orcid.org/0000-0003-1088-1457, Jinping He https://orcid.org/0000-0002-1899-3384), this kind of spectral technology can realise both ultra-high resolution (0.5~10 million) and ultra-high wavelength calibration accuracy (10 cm/s) with compact device and low cost by optimizing the system to control the temperature and pressure of the device which can provide support for future astronomical ultra-high resolution spectral observation.

The VIPA spectrograph has promising applications in various astronomical observations in which ultra-high resolution and calibration precision are imperative, such as solar physics research, exoplanet searching with the radial velocity method, and O2 detection in the atmosphere of Earth-like planets.