P.P. Iannone

A wavelength-division multiplexed passive optical network with cost-shared components

We demonstrate a passive optical network (PON), based on a wavelength-division multiplexing router, with modulators (instead of lasers) at the subscriber terminals. A single, cost-shared, tunable laser is time-division multiplexed to provide bidirectional switched WDM services for N subscribers with independent formats and bit-rates for each. Simultaneous support of telephony and compressed digital video are presented in which RF subcarrier multiplexing is used to provide service segregation and resolve upstream packet contention.<<ETX>>

FDMA-FSK star network with a tunable optical filter demultiplexer

An optical frequency-division-multiple-access (FDMA) star network is analyzed and demonstrated experimentally using two 45-Mb/s frequency-shift-keyed (FSK) laser channels at 1.5 mu m. A tunable fiber Fabry-Perot (FFP) filter is used to select channels and convert FSK to intensity modulation for direct detection. The analysis predicts and experiment supports a minimum channel spacing of about six times bit rate B for a single FFP. These constraints are similar to those for more complex heterodyne demultiplexing. Estimates show that a network with 1000 users, independent of bit rate, is feasible with a tandem FFP. For B=1 Gb/s per channel the network capacity would be 1 Tb/s. >

A spectrally sliced PON employing Fabry-Perot lasers

We investigate using Fabry-Perot lasers as the upstream transmitters in a wavelength-division-multiplexed passive optical network (WDM-PON). We demonstrate transmission of a 10-Mb/s signal through each port of a wavelength-grating router followed by 18 km of fiber using an uncooled Fabry-Perot laser. These signals could be subcarrier multiplexed together, so that each user would have a dedicated radio-frequency channel. Since Fabry-Perot lasers provide more output power than low-cost light-emitting diodes, this may enable deployment of WDM-PONs in areas where optical loss prohibits the use of other low cost optical sources. The bit-rate is limited by mode-fluctuations being converted into intensity noise when transmitted through the router.

Wide-band lightwave distribution system using subcarrier multiplexing

A description is given of a bidirectional lightwave distribution system based on subcarrier multiplexing. Eight independent wideband channels (180 Mb/s/channel) are transmitted from the head-end on one 1.3- mu m wavelength laser as frequency-shift-keyed (FSK) subcarriers, between 2.6 and 4.7 GHz. Each receiving node uses a parallel-resonant p-i-n FET receiver, a microwave bandpass filter and a limiter-discriminator demodulator to select and demodulate the appropriate channel. A 45-Mb/s return channel is provided from each node to the head-end on a separate subcarrier frequency. Error-free bidirectional transmission is obtained without penalties from laser nonlinearities, optical reflections or interference, or interchannel interference from closely spaced subcarrier channels. >

A tunable Vernier fiber Fabry-Perot filter for FDM demultiplexing and detection

An N-channel optical frequency-division multiplexing (FDM) network can be realized using frequency-shift keying (FSK) modulation and a tunable filter to select and detect the channels. A tandem arrangement of two fiber Fabry-Perot (FFP) filters is demonstrated. For FFPs with individual finesse (F) of 57 an effective finesse of 675 is obtained in a tandem arrangement. This has a capacity of N=F/3=225 channels in a frequency-division multiaccess (FDMA)-FSK network.<<ETX>>

High-speed point-to-point and multiple broadcast services delivered over a WDM passive optical network

Tailoring broad optical sources to the free spectral range of a waveguide-grating router, we show that multiple independent broadcast services can be delivered efficiently over a common wavelength-division-multiplexed passive optical network (PON). In addition to 1) delivering two independent video services, each comprising 80 digital video channels, we further exploit the periodicity property of the router to simultaneously deliver; 2) bidirectional 50-Mb/s baseband conventional PON service; 3) a limited (50 channel) digital broadcast video service; and 4) an individual 2.5-Gb/s bidirectional link to a business subscriber, demonstrating several distinct upgrade paths. Bit-error-rate performance and dispersion measurements are presented.

Broadcast digital video delivered over WDM passive optical networks

A robust broadcast digital video upgrade for high-performance WDM passive optical networks is demonstrated. The video format is derived from a commercially available direct satellite TV service. We broadcast 81 high-quality digital video channels and 29 audio channels, while simultaneously demonstrating error-free bidirectional transmission over two types of WDM PONs: the first is an entry-level system, which uses low-cost broad-band LED sources; the second (RITE-Net) is a high-performance network, which shares a single 1.5-/spl mu/m tunable laser source among all subscribers to provide virtual point-to-point connectivity. The broadcast upgrade is implemented by adding a directly modulated 1.3-/spl mu/m uncooled LED transmitter at the central office and an ac-coupled receiver at each subscribers optical network unit. The outside fiber plant remains unaltered.

Spectral slicing in WDM passive optical networks for local access

Spectral slicing techniques can support point-to-point, point-to-multipoint, and multiple access applications in the local access network. With spectral allocation it enables operation of multiple independent networks on a common infrastructure, with partitioning of both services and quality of service.

RITE-Net: A Passive Optical Network Architecture Based on the Remote Interrogation of Terminal Equipment

Current passive optical networks (PONs) utilize a splitter at the remote node (RN) to distribute signals from a central office (CO) to N subscribing optical network units (ONUs). Although commercially attractive for low rates [1], the bus’ optical loss hampers future upgrades and TDM/TDMA protocols add network vulnerability if violated. WDM PONs have been proposed [2,3], but have not been accepted due to costly wavelength-specific lasers and the complexity of locking their 2N wavelengths to a remote WDMs wavelength channels.

40-Gb/s TDM-PON over 42 km with 64-way power split using a binary direct detection receiver

We demonstrate a 40-Gbps TDM-PON over a 42-km, 64-split fiber plant using optical duobinary modulation. Experimental results show that our architecture supports 31 dB of power budget for a differential reach of 26 km at 1550 nm without DSP.