We demonstrate a simplified configuration of an ultrafast walk-off-free nonlinear optical loop mirror (NOLM) for 320-10-Gbit/s optical time-division demultiplexing. The proposed NOLM consists of a short, 100-m length of highly nonlinear dispersion-shifted fiber, resulting in compact, highly stable, and ultrafast walk-off-free operation. (C) 2002 Optical Society of America.