Abstract: Angle measurement,a core task in physics,has advanced from geometric methods to highly precise technologies.It plays a critical role in scientific research,precision manufacturing,and satellite positioning.However,traditional angle measurement methods,including non-interference methods,interference methods,electromagnetic,and inertial method,face inherent limitations in resolution.To address this limitation,an angle-to-frequency conversion measurement technique has been proposed.Leveraging the high sensitivity of narrow-band interference filter external cavity diode lasers (ECDLs) to angular changes of the interference filter,the filter is fixed to the measured object,converting small angular variations into changes in the laser frequency.By using a stable reference frequency source and employing beat frequency comparison,the frequency shifts of the output laser are precisely detected,enabling ultra-high-precision angular measurements of the device.Compared with traditional angle measurement methods,this approach transforms angular measurement into frequency measurement,significantly enhancing the capability for precision measurements of small angles,aiming to achieve an angular resolution on the order of 0.000 1 arcseconds.

Key words: Interference filter, External cavity diode laser, Angle measurement, Time-frequency measurement, Angle resolution