title: Ultracompact waveguide bends with simple topology in two-dimensional photonic crystal slabs for optical communication wavelengths.
abstract: Ultracompact waveguide bends with simple topology in two-dimensional photonic crystal slabs are proposed by using an annular air groove at the bend corner to improve transmissions of the bends. Analysis indicates that the guided light wave experiences a very slight difference of propagation properties between straight waveguides and bends (with 60 degrees and 120 degrees bending angles). Transmissions of more than 90% can be achieved in the 60 degrees and 120 degrees bends for light waves at 1.55 microm with bandwidths of 101 and 74 nm, respectively.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Baojun
authors.initials: B
authors.lastname: Li