Conical holes arrays for 2 x 2 ports division

The 2 x 2 ports division is introduced based on novel conical holes arrays in this paper. Under the normal incidence of wavelength 780 nm, the grating can achieve high efficiency in the orders (+/- 1, 0) and (0, +/- 1) which are 24.28% and 24.33%. The uniformity (E U) and the extinction rate (E T) are 0.10% and 21.10 dB. Furthermore, the numerical analysis indicates that the proposed grating exhibits a large angular bandwidth of 11 degrees and a wavelength bandwidth of 34 nm when the target condition has diffraction efficiency above 20% for all main diffraction orders. What's more, the results demonstrate that the proposed grating is feasible for practical manufacturing by exhibiting good manufacturing tolerances and high performance. The performance of the grating is so excellent that it has a wide application prospect in interferometers, spectroscopy, optical communications, etc.