LAUSR

Abstract In this paper, we design two kinds of one-dimensional (1D) equal-length two-segment-connected periodic triangular optical waveguide networks with different PT-symmetric degrees, one-dimensional PT-symmetric triangular optical waveguide network (1D PT-TOWN) and one-dimensional non-PT-symmetric triangular optical waveguide network (1D nPT-TOWN). It is found that no matter whether the network is PT-symmetric or non-PT-symmetric, as long as a PT-symmetric unit exists, both gain and loss photonic nonpropagation modes will be created and their frequencies are all the same. Consequently, ultrastrong extraordinary transmissions can be generated by two networks, which can arrive at 2 . 2 × 1 0 6 and 8 . 7 × 1 0 4 respectively. However, because the PT-symmetric degree of the former is higher than the latter, the transmission of the former is two orders of magnitude larger than the latter. Therefore, The PT-symmetric degree influences seriously on the photonic modes distribution and transmission of the network. Our research may deepen people’s understanding of PT symmetry, which has potential application to the design of high-efficiency photon energy storage device, optical switches, optical amplifiers, and so on.