Application of fiber-integrated technology in astronomical spectral observation

Optical fiber spectroscopy technology is widely used in astronomical surveys. Due to the flexibility and long-distance transmission characteristics of the fiber, astronomical observation can gain larger scale and higher precision spectral data. Nowadays, a lot of representative technologies have been presented to enhance spectral resolution, including fiber integral field spectroscopy, fiber positioning technology in the sky survey, adaptive optics, and photonic lantern technology. The intrinsic flexibility of fibers lends itself readily to reconfigurable sampling of the field. Fiber integral field spectroscopy is one of the most typical techniques to enhance the spectrum resolution. The flexible combination of fiber bundle and microlens is used to improve the sampling rate of target stars and fitting factor. In the observation of target stars by a single fiber, the alignment accuracy between the fiber and the star image determines the spectrum resolution. In the multi-object telescope, the position of a large number of multi-mode fibers needs to be detected. Photonic lantern can convert the energy collected by multi-mode fiber into the output of single-mode fiber.