Wavelength-division multiplexing

About: Wavelength-division multiplexing is a research topic. Over the lifetime, 25059 publications have been published within this topic receiving 332027 citations. The topic is also known as: WDM.

No-Guard-Interval Coherent Optical OFDM for 100-Gb/s Long-Haul WDM Transmission

Abstract: This paper describes coherent optical orthogonal frequency division multiplexing (CO-OFDM) techniques for the long-haul transmission of 100-Gb/s-class channels. First, we discuss the configurations of the transmitter and receiver that implement the optical multiplexing/demultiplexing techniques for high-speed CO-OFDM transmission. Next, we review the no-guard-interval (No-GI) CO-OFDM transmission scheme which utilizes optical multiplexing for OFDM signal generation and the intradyne receiver configuration with digital signal processing (DSP). We examine the transmission characteristics of the proposed scheme, and show that No-GI CO-OFDM offers compact signal spectra and superior performance with regard to tolerance against optical amplifier noise and polarization-mode dispersion (PMD). We then introduce long-haul high-capacity transmission experiments employing No-GI CO-OFDM; 13.4 Tb/s (134 times 111 Gb/s) transmission is successfully demonstrated over 3600 km of ITU-T G.652 single-mode fiber without using optical dispersion compensation.

Optical multiplexing device

Abstract: An optical multiplexing device spatially disburses collimated light from a fiber optic waveguide into individual wavelength bands, or multiplexes such individual wavelength bands to a common fiber optic waveguide or other destination. The optical multiplexing device has application for dense channel wavelength division multiplexing (WDM) systems for fiber optic telecommunications, as well as compact optical instrument design. Multiple wavelength light traveling in a fiber optic waveguide is separated into multiple narrow spectral bands directed to individual fiber optic carriers or detectors. An optical block has an optical port for passing the aforesaid multiple wavelength collimated light, and multiple ports arrayed in spaced relation to each other along a multiport surface of the optical block. A continuous, variable thickness, multi-cavity interference filter extends on the multiport surface of the optical block over the aforesaid multiple ports. At each of the multiple ports the continuous interference filter transmits a different wavelength sub-range of the multiple wavelength collimated light passed by the optical port, and reflects other wavelengths. Multicolor light passed to the optical block from the optical port is directed to a first one of the multiple ports on an opposite surface of the optical block. The wavelength sub-range which is "in-band" of such first one of the multiple ports is transmitted through that port by the local portion of the continuous, variable thickness interference filter there, and all other wavelengths are reflected. The light not transmitted through the first port is reflected to strike a second port, at which a second (different) wavelength band is transmitted and all other light again reflected. The reflected optical signals thus cascades in a "multiple-bounce" sequence down the optical block of the multiplexing device, sequentially removing each channel of the multiplexed signal. In reverse operation, individual channels are combined in the optical block and transmitted through the optical port.

Wavelength-selective 1/spl times/K switches using free-space optics and MEMS micromirrors: theory, design, and implementation

Abstract: The design and performance of several generations of wavelength-selective 1/spl times/K switches are reviewed. These optical subsystems combine the functionality of a demultiplexer, per-wavelength switch, and multiplexer in a single, low-loss unit. Free-space optics is utilized for spatially separating the constituent wavelength division multiplexing (WDM) channels as well as for space-division switching from an input optical fiber to one of K output fibers (1/spl times/K functionality) on a channel-by-channel basis using a microelectromechanical system (MEMS) micromirror array. The switches are designed to provide wide and flat passbands for minimal signal distortion. They can also provide spectral equalization and channel blocking functionality, making them well suited for use in transparent WDM optical mesh networks.

Wavelength conversion using semiconductor optical amplifiers

Abstract: This paper reports a detailed theoretical study of the dynamics of wavelength conversion using cross-gain and cross-phase modulation in semiconductor optical amplifiers (SOA's) involving a large signal, multisection rate equation model. Using this model, recently reported experimental results have been correctly predicted and the effects of electrical and optical pumping on the conversion speed, modulation index, and phase variation of the converted signal have been considered. The model predicts, in agreement with experimental data, that recovery rates as low as 12 ps are possible if signal and pump powers in excess of 14 dBm are used. It also indicates that conversion speeds up to 40 Gb/s may be achieved with less than 3 dB dynamic penalty. The employment of cross-phase modulation increases the speed allowing, for example, an improvement to 60 Gb/s with an excess loss penalty less than 1 dB.

All-optical signal processing for terabit/second optical transmission

Abstract: Recent progress toward multiterabit/s optical transmission systems employing all-optical ultrafast signal-processing technologies is described. Focus is placed on optical time-division multiplexing (OTDM), as well as optical time- and wavelength-division multiplexing (OTDM/WDM) technologies leading to multiterabit/s transmission capacity. The key technologies, including ultrafast pulse generation, all-optical multiplexing/demultiplexing, and optical timing extraction techniques, are also described, together with state-of-the-art performances and future prospects.