Optical solitons for coupled Fokas–Lenells equation in birefringence fibers

This paper discusses bright, dark and singular optical soliton as well as complexiton solutions to the coupled Fokas–Lenells equation (FLE) for birefringent fibers by three integration tools such as [Formula: see text]-expansion method, the first integral method and the sine-Gordon expansion method. The existence criterion of these solutions is also given.