title: Note: Autocollimation with ultra-high resolution and stability using telephoto objective together with optical enlargement and beam drift compensation.
abstract: An autocollimation (AC) setup with ultra-high resolution and stability for micro-angle measurement is presented. The telephoto objective, which is characterized in long focal length at a compact structure size, and the optical enlargement unit, which can magnify the image displacement to improve its measurement resolution and accuracy, are used to obtain an ultra-high measurement resolution of the AC. The common-path beam drift compensation is used to suppress the drift of measurement results, which is evident in the high-resolution AC, thus to obtain a high measurement stability. Experimental results indicate that an effective resolution of better than 0.0005 arc sec (2.42 nrad) over a measurement range of ±30 arc sec and a 2-h stability of 0.0061 arc sec (29.57 nrad) can be achieved.
authors: Postdoctoral Research Station of Optical Engineering, Harbin Institute of Technology, Harbin 150080, China.
authors: Fan
authors: F
authors: Zhu
authors: Center of Ultra-precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin 150080, China.
authors: Xinran
authors: X
authors: Tan
authors: Center of Ultra-precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin 150080, China.
authors: Jiubin
authors: J
authors: Tan
authors: Postdoctoral Research Station of Optical Engineering, Harbin Institute of Technology, Harbin 150080, China.
authors: Zhigang
authors: Z
authors: Fan