Application of stereomicroscope and CCD imaging system to spot size measurement of high-order Bessel beam

This article mainly analyzed the application of optical measuring instruments, stereomicroscope and CCD imaging system to the spot measurement of high-order Bessel beam. By taking the high-order Bessel beam which is generated when incoherent LED green light is passing through the spiral phase plate and axicon as an example, we simulated the cross-section intensity distribution at different distances along the axial direction, and it is compared to corresponding experimental parameters, such as maximum non-diffracting distance, central spot diameter etc. The experimental result shows that the measurement results of stereomicroscope and CCD imaging system are in good agreement, but there are different merits and demerits between these two instruments, and the measurement error of stereomicroscope will affect the accuracy of measurement results.