This paper proposed and experimentally demonstrated the effective design of a single-to-dual channel 100 Gbit/s wavelength converter with a simple configuration consisting of a single dispersion flattened highly nonlinear photonic crystal fiber (DS-HNL-PCF) and two optical bandpass filters (OBPFs). The polarity-preserved, ultrafast wavelength conversion with single-to-dual channel multicasting is achieved by simultaneously filtering the red- and blue-chirped spectral component of a probe light. Moreover, the wavelength tunability and dynamic characteristics of designed wavelength converter are investigated. The results show that the designed ultrafast wavelength converter has a wide wavelength conversion range of 29 nm, and high tolerance to input power fluctuations. It is very attractive for engineering application in modern microwave and ultrafast photonic networks.