Talbot effect of ring laser array realized by Gyrator canonical transformation br

We propose a ring laser array structure and study the Talbot effect. By comparing with the one-dimensional laser array, the near-field distribution of the identical intensity of the ring laser array without edgeeffect is obtained, which can be more conducive to improving the capability of the external cavity phase lockingof lasers. In this paper, Talbot effect and self imaging condition of ring laser array in polar coordinates arecalculated by using Gyrator canonical transformation. The sub-image distribution at the fractional Talbotdistance is further analyzed. The optical profile and phase distribution of the ring laser array at the fractionalTalbot distance are simulated, which are mutually verified with the theoretical calculation results. At a quarterof the Talbot distance, the number of sub-images is twice that of the emitters. The light intensities of the sub-images are identical, and thedifference in phase between adjacent sub-images is . At half of the Talbotdistance, the number of sub-images is the same as that of the emitters, while the spatial position of sub-image isshifted by half a cycle along the angular direction. Moreover, the sub-images with twice the number of theemitters are present in three quarters of the Talbot distance. The light intensities of the sub-images areidentical and the difference in phase between adjacent sub-images is . Further, the Talbot images with thesame spatial and phase distribution as the emitters are generated along the angular direction at the Talbotdistance. The optical profile and phase distribution of one dimensional laser array at the fractional Talbotdistance are also simulated by FDTD Solutions for comparison. It is found that the edge effect of one-dimensional laser array leads to the uneven distribution of near-field light intensity, in which the intensity oflight spot on the edge of array is significantly lower than that in the center of array. While the Talbot sub-images of ring laser array with identical light intensity are obtained. Therefore, We consider that the ring laserarray can effectively eliminate the edge effect. The results are helpful in studying the external cavity phaselocking of ring laser arrays and its applications in the field of high brightness coherent laser and quantum measurement