Calibration method for broadband optical angle measurement

We propose a self-calibration method for optical angle measurement using a broadband light source and a grating. To the present, these angle measurement methods have used the detector installation angle and grating pitch as known measurement parameters, or the detector installation angle is measured by external reference sensor. These measurement methods employ optical frequency comb as a light source. One of advantages of the frequency comb is that the frequency of comb is calibrated remotely by atomic clocks in GPSs. However, if an external sensor is needed to calibrate the measurement system, the external sensor also needs to be calibrated, thus eliminating the significance of using an optical frequency comb. In this study, the self-calibration method to determine the setting angle of fiber detector and grating pitch without using external angle sensors is proposed and the method is also demonstrated with experiment.