A novel 1 × N optical power splitter has been proposed, to realize the desired specific optical power splitting, in which the asymmetric Y-branch waveguides based on total internal reflection have been introduced. The simulated results show that the arbitrary expected splitting can be achieved in the device. The device has been fabricated by using polymer materials, and it experimentally exhibits good uniformity at optical power output ports, which is consistent with the simulation prediction. The novel 1 × N optical power splitter has wide potential application in the integrated optical system.