A VIPA spectrograph with ultra-high spectral resolution, ultra-high wavelength calibration accuracy and wide spectral range

Spectrographs with ultra-high spectral resolution, ultra-high wavelength calibration accuracy, and wide spectral range hold immense potential in broad scientific frontiers, such as precise spectral measurement, femtosecond pulse shaping, and spectral beam combining, etc. In this paper, we have constructed a virtually imaged phased array (VIPA) based spectrograph, leveraging a laser frequency comb for precise wavelength calibration. The calibration methods specifically for the broadband VIPA spectrograph are presented. The spectrograph achieves a resolution exceeding 650000, a wavelength calibration accuracy better than 0.05 pm, and a remarkable bandwidth of over 110 nm. Spectral measurements are conducted with the spectrograph, and the results validate the performance.