A device is configured for treating pathological narrowing of fluid-carrying conduits of the human body (such as blood vessels) in an area of a bifurcation (30). In particular, a stent delivery system (100) configured to carry one or more of a pair of dissimilar stents (12, 14). At least one of the stents (12, 14) is particularly suited for treating a widened portion of a blood vessel (46) immediately proximal to a bifurcation (30). The stent delivery system (100) can also include a handpiece (140) adapted to selectively deliver the stents.

Endoprosthesis deployment system for treating vascular bifurcations

A communications network has a plurality of nodes interconnected by an optical transmission medium. The transmission medium is capable of a carrying a plurality of wavelengths organized into bands. A filter at each node for drops a band associated therewith and passively forwards other bands through the transmission medium. A device is provided at each node for adding a band to the transmission medium. Communication can be established directly between a pair of nodes in the network sharing a common band without the active intervention of any intervening node. This allows the network to be protocol independent. Also, the low losses incurred by the passive filters permit relatively long path lengths without optical amplification.

WDM optical network with passive pass-through at each node

This article provides a perspective on optical layer protection and restoration based on the services offered by carriers using the optical layer. This is different from other viewpoints that provide a taxonomy of protection techniques in a more abstract fashion for the purposes of standardization. The latter viewpoints are mostly based on the classification adopted in the SONET/SDH standards. In contrast, taking a services-based view provides a way to distinguish between protection schemes based on implementation costs and the associated services enabled by the protection scheme.

Optical layer survivability: a services perspective

An optical multi-channel data communication link transmits data from a transmitter to a remote receiver. The link includes a multimode laser diode source connected to the transmitter, a device for modulating the source with each channel of data to generate a modulated light wave, and a wavelength division multiplexing device at the transmitter. The wavelength division multiplexing device has paraxial optics for multiplexing the light waves to produce a multiplexed signal. Multimode fiber optic means are connected to the multiplexer and pass the multiplexed signal to the remote receiver. A wavelength division multiplexer has paraxial optics for demultiplexing the multiplexed signals at the receiver to produce demultiplexed light waves. Each of the demultiplexed light waves are converted for use by the receiver. Preferably, each of the wavelength division multiplexer and demultiplexer has a littrow reflecting grating and a lens which are paraxially aligned with the multimode fiber optic means to provide channel separation of less than 50 nm.

Multiwavelength data communication fiber link

A method and system for detecting optical signal degradation or loss within the optical domain of a fiber network. Optical cross-connect switches (OCCS) are provided at network nodes. Optical data traffic is conducted between nodes via a fiber link. The fiber link extends between respective ports of the optical cross-connect switches at each network node. Dedicated signals for detecting faults are introduced and removed within the optical domain of the fiber communication network. In one embodiment, transmitter/receiver units are coupled directly to the fiber link for broadcasting optical signals for fault detection. In another embodiment, transmitter/receiver units are coupled to the fiber link through one or more dedicated ports within optical cross-connect switches (OCCS) at network nodes. Optical signals for fault detection are then broadcast or switched through working and/or spare fibers. Distinctive optical fault detection signals are used when the signals are broadcast or switched over working fibers. Optical signal impairment or loss for a particular link or span is detected simply and quickly in the network optical domain. Rapid, accurate optical fault capability can be added to communication networks without requiring changes to existing light terminal elements and processing circuitry in the electrical domain.

Method and system for detecting optical faults within the optical domain of a fiber communication network

An optical repeater for realizing transmission of supervisory information of an optical fiber transmission system without the output power of an optical fiber amplifier being reduced, wherein a supervisory optical transmitter and optical receiver with a wavelength which is similar to the wavelength of the pumping light source of the optical fiber amplifier are mounted, and on the input side of the optical repeater, pumping light is multiplexed in the forward direction and a supervisory optical signal, which is multiplexed in wavelength and transmitted, is demultiplexed simultaneously by the first wavelength multi- and demultiplexer and they are received by the supervisory optical receiver, and on the output side of the optical repeater, pumping light is muitiplexed in the reverse direction and a supervisory optical signal outputted from the supervisory optical transmitter is multiplexed by the second wavelength multi- and demultiplexer.

Optical fiber transmission system and supervision method of the same

A wavelength division multiplex communication system comprises a head station (2) and a plurality of terminal stations (1) interconnected by an optical fibre cable (3). The head station (2) transmits continuous wave modulated wavelengths (μ1-μk), and a signalling wavelength (μ0) which is used to indicate, in each time slot, which wavelengths in the following time slot are available for transmission. Each terminal station (1) is arranged to receive the signalling wavelength, to determine therefrom whether the next time slot contains any data packets for that terminal station and, if so, to receive the packets. The terminal station (1) is arranged, if it has a data packet to transmit, to determine from the signalling wavelength whether the next time slot already contains data packets for the destination station and, if so, to avoid data collision by not transmitting its own data packet. The terminal station (1) then determines a free wavelength (μq) from the signalling wavelength (μ0), modulates the free wavelength with the data packet it is to transmit, and modifies the signalling wavelength.

Wdm network with control wavelength

A wavelength division multiplex communications system has a head station and a plurality of terminal stations interconnected by an optical fiber cable. The head station transmits CW modulated wavelengths (λ- 1 -λ k ), and a signalling wavelength (λ 0 ) which is used to indicate, in each time slot, which wavelengths in the following time slot are available for transmission. Each terminal station is arranged to receive the signalling wavelength (λ 0 ), to determine therefrom whether the next time slot contains any data packets for that terminal station and, if so, to receive the packets. Each terminal station is arranged, if it has a data packet to transmit, to determine from the signalling wavelength (λ 0 ) whether the next time slot already contains data packets for the destination station and, if so, to avoid data collision by not transmitting its own data packet. The terminal station then determines a free wavelength (λ t ) from the signalling wavelength (λ 0 ), modulates the free wavelength with the data packet it is to transmit, and modifies the signalling wavelength.

Wavelength division optical signalling network apparatus and method

PURPOSE:To obtain an optical multiplexer and demultiplexer which is small in size and has a good extinction ratio and S/N ratio by setting the thickness, etc. of the optical waveguide layer parts positioned on both sides of a directional coupler in such a manner that the light of one wavelength transfers thoroughly from one optical waveguide to the other waveguide and that the light of the other wavelength propagates hardly in the optical waveguides. CONSTITUTION:The optical waveguide layer 4 and ridge type optical waveguides 1, 2 are provided by using a material having a high refractive index on a substrate 5 consisting of GaAs, etc. The thickness of the optical waveguide layer is so set that the thickness ta in the region part A positioned on both sides of the ridge type optical waveguides 1 and 2 and the film thickness te in the region part B positioned between the waveguides 1 and 2 differ from each other. The optical waveguides and the optical waveguide layer are so formed that the propagation characteristics thereof vary with the light of the prescribed wavelength and the light of the other wavelength. The height (h), width W and space (d) of the ridges are so set that the light of the prescribed wavelength are thoroughly coupled in the coupling section.

Optical multiplexer and demultiplexer

A system for stabilizing a frequency separation between two coherent light sources includes first and second current sources driving first and second semiconductor laser devices with first and second frequencies, respectively. Light from the semiconductor laser devices is combined in a multiplexer, and a portion the combined light is diverted to an optical-to-electrical transducer. Output current from the transducer is combined with an output of a local oscillator driven at a selected frequency. A combined signal is then filtered, and used to form a control signal of one of the semiconductor laser devices.

Hideaki Tsushima

Papers

Optical fiber transmission system and supervision method of the same

Wdm network with control wavelength

Wavelength division optical signalling network apparatus and method

Optical multiplexer and demultiplexer

Frequency separation stabilization method for optical heterodyne or optical homodyne communication