Xiaofei Cheng

This letter demonstrates a novel coding technique to accurately detect the faulty branch in time-division-multiplexing passive optical network (TDM-PON) infrastructure. The notion relies on encoding the probe signal with a novel composite structure coding technique to achieve the advantages of improved signal-to-noise ratio and resolution, reduced measurement time, and simplified complexity of branch identification. Proof-of-concept experiments on a constructed 1 × 32 TDM-PON with 20 km feeder fiber have been demonstrated, the experimental results are consistent with theoretical results and confirm the key advantages.

This paper presents a new passive optical network (PON) architecture that applies an optical multicast capable switch (OMS) to direct wavelengths to a set of PON branches and enables them to share the transceivers in the central office (CO) on demand. The OMS is composed of fiber splitters and switching gates, and by controlling the on-off gates the wavelengths at the inputs can reach any outputs of the OMS. Through the OMS configuration, logical PONs are dynamically formed according to changing traffic patterns, and traffic is further scheduled in the time domain within each logical PON. The proposed network achieves network resource sharing without requiring tunable transceivers or wavelength filters, and without changing deployed network devices in the field or at the user end. Analysis and experimental study results show the efficiency of resource sharing and demonstrate the concept of resource sharing among PON branches.

We propose a method to precisely detect the faulty branch of time-division-multiplexing-passive optical networks (TDM-PONs) by encoding the probe signal with optical orthogonal codes. The proposed technique projects each probe signal response onto an orthogonal space, wherein an event corresponding to each branch of the TDM-PON is uniquely mapped onto an orthogonal basis and thereby able to isolate the origin of the event to a particular branch. A proof-of-concept experiment is carried out on a 1 × 16 TDM-PON with 20 km feeder fiber and the results confirm that, with the proposed design the system can support up to 120 m branch fiber length with 3 m spatial resolution.

In this paper, we introduce our Home2015 project - wavelength-agile optical access networking system. We propose a multi-wavelength access network to offer higher system capacities for next-generation optical access. Our proposed concept of virtual PON (VPON) is introduced to realize dynamic ONU re-grouping functionality. Optical network units (ONUs) in the PON system can dynamically form different TDM-PON by using a different downlink and uplink wavelength channel. Novel photonic silicon chip integration techniques are introduced to reduce size and cost of the ONUs. We also introduce our works on live 3D hologram video transmission platform design and live 3D hologram video transmission via the 10-Gb/s wavelength-agile optical access network. Our demostration shows that our system has good transmission performances.

We mathematically analyze and experimentally investigate the characteristics of subcarrier-modulated (SCM) light. Our investigation shows that the baseband data are also carried on the optical carrier after subcarrier modulation. This residual data introduce crosstalk when the optical carrier is separated from subcarriers and reused for uplink data modulation. The influence of the residual data carried on the optical carrier is studied in three kinds of upstream transmissions based on wavelength-seeded reflective semiconductor optical amplifiers (RSOAs) for carrier-reuse wavelength-division-multiplexed-passive optical networks (WDM-PONs). Results show that the crosstalk can be significantly suppressed with proper selection of the seeding power and operation conditions of downlink Mach-Zehnder modulator (MZM), including driving voltage and bias voltage.