Proposed is a novel structure of a cascadable photonic serial-to-parallel converter (SPC) based on the cross-phase modulation effect in a semiconductor optical amplifier for simultaneous multiple-channel optical time division multiplexed demultiplexing. The proposed SPC features cascadability, compact structure, high-speed operation, and simultaneous two-channel operation. Error-free 20 Gbit/s simultaneous two-channel demultiplexing is experimentally demonstrated.Introduction: Simultaneous multiple-channel processing, which is capable of providing several advantages such as low latency, low insertion loss, and easy synchronisation, is a key technique for optical time division multiplexed (OTDM) networks [1]. However, most of the reported OTDM demultiplexers are focused on processing individual channels using semiconductor optical amplifier (SOA)-, fibre-and electro-absorption modulator (EAM)-based optical gates [2 -4]. There are only a few approaches for multiple-channel OTDM demultiplexing. Morais et al. demonstrated a demultiplexer using both wavelength conversion and time gating techniques [5]. Uchiyama et al. reported two approaches based on cross-phase modulation (XPM) in polarisationmaintaining dispersion-shifted fibres and four-wave mixing (FWM) in SOAs [6, 7]. Furthermore, Dennis et al. employed a series of modulators to perform serial-to-parallel conversion for eight-channel full demultiplexing [8].In this Letter, we propose and demonstrate a new structure of an all-optical serial-to-parallel converter (SPC) for multiple-channel OTDM demultiplexing. The proposed SPC features cascadability, compact structure, high-speed operation, and simultaneous twochannel operation. Cascading several SPCs can provide the possibility to extend the number of ultimate outputs. A proof-of-concept experiment is carried out to demonstrate error-free operation of simultaneous two-channel demultiplexing for a 20 Gbit/s OTDM signal.