Abstract: A disposable cover for electromagnetic treatment applicators prevents undesired exposure to potentially harmful radiation. The cover is a pouch-like structure having a back surface (which faces opposite, or away from, the treatment area) constructed from shielding material, such as metallized polyethylene. At least a portion of the cover which faces the treatment area is constructed solely from non-shielding material. Adhesive strips, ZIP-LOCK®, or other interlocking edges, secure the applicator inside the cover and close off any leaks. The electromagnetic properties of the cover are integrated into the circuitry for the treatment applicator, such that the applicator is not functional in the absence of the cover. In use, an electromagnetic treatment applicator is inserted into the cover and positioned over the area to be treated, with the non-shielding, or “window”, portion of the cover overlying the treatment area.

Abstract: An optical switch includes: at least a light transmission portion, an optical path-changing portion and an actuator portion. The light transmission portion has a light reflecting plane and light transmission channels having optical wave guiding bodies provided in at least three directions. The optical path-changing portion is proximate the light transmission portion in a movable condition and is made to contact or separate from the light transmission portion. An optical path where light input to the light transmission channels is totally reflected in the light transmission portion and is transmitted to a specific light transmission channel on an output side, is switched to another optical path where light input to the light transmission channel is taken to the light introduction member, and is totally reflected at the light reflection member and is transmitted to a specific light transmission channel on the output side.

Abstract: An optical multiplexer device comprising: a first optical input channel; a second optical input channel; an optical output channel; a first series of polarization manipulation elements inconnected to the first and second input channel, the elements manipulating the polarization state of light emitted from either the first or second input channel; a wavelength selective filter adapted to transmit first predetermined wavelengths and reflect second predetermined wavelengths emitted from the first and second optical channel; a second series of polarization manipulation elements for manipulating the first predetermined wavelengths; wherein input light from the second optical input channel having third predetermined range of wavelengths is combined with light emitted from the first optical input channel at the optical output channel.

Abstract: An optical transmission system designed for gigabit pulse rates and Raman pumping in which there is essentially no pre-dispersion compensation and the in-line dispersion compensation at the start of each span is overcompensation of between 110 and 120 of the compensation needed to neutralize the dispersion of its immediately preceding span.

Abstract: A method and apparatus within an optical transmitter (300) for suppressing relative intensity noise (RIN) by generating at least two optical signals (305,310), each having differing wavelengths and combining the optical signals with a combiner (315) into a composite output signal, wherein the composite output signal has an output power value equal to the sum of the power value of the optical signals. The composite output signal is then transmitted over a communication medium, wherein information content of the optical signals are substantially equivalent, and wherein combining the optical signals before transmitting provides a reduction in RIN of the composite output signal compared to the RIN of a single optical signal transmitted over a communication medium.

Abstract: Optical transmission systems of the present invention include at least one optical amplifier generally including an optical signal amplifying medium supplied with pump power in the form of optical energy in via an optical pump source. The pump source includes multiple optical sources, at least two of which provide optical energy in first and second wavelength ranges separated by a frequency difference. The amplifier includes a wavelength controller configured to adjust the wavelength range of at least one of the optical sources to vary the frequency difference in a manner sufficient to vary optical intensity noise produced when the optical energy from the multiple optical sources is combined.

Abstract: The invention relates to an arrangement for operating an optical transmission or reception module at high data rates of up to 10 Gbit/s, having a TO package with electrical connections, an optical transmission or reception module arranged in the TO package, and a circuit board for making electrical contact with the electrical connections of the TO package. According to the invention, the circuit board (6) has RF lines (81, 82) and the electrical connections (41, 42) are connected to the RF lines (81, 82) in an arrangement parallel to the plane of the board. Preferably, provision is also made for an RF matching circuit to be produced on the board and for SMD components to be fitted directly and without further solder pads onto planar RF lines on the RF board. The cited measures serve to improve the RF properties of a TO module.

Abstract: A polarization mode dispersion (PMD) compensation arrangement receives an optical input data signal which has been subjected to PMD. The arrangement comprises an adaptive chromatic dispersion compensator (24) and a first-order PMD compensator (20,22) in series, wherein the adaptive chromatic dispersion compensator is controlled to provide compensation for both chromatic dispersion and second order PMD. The compensation arrangement is used in a node of an optical network.

Abstract: This invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral channels, which are focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into selected output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the invention may further employ a polarization diversity scheme, whereby polarization-sensitive effects become inconsequential and insertion loss is minimized. The WSR apparatus of the invention may additionally be equipped with servo-control and channel equalization capabilities.

Abstract: A soliton or soliton-like pulse-based optical communication system comprises a length of optical fibre divided into a plurality of sections arranged so that the average dispersion of the length of fibre is significantly different from the dispersion of each section.

Abstract: A method of transmitting bidirectional telephony communication signals on a single optical fiber. The bidirectional signals are transmitted in one direction as NRZ coded signals at a first clocking pulse rate, and in the other direction as modified a hybrid form of ON-OFF keying coded signals having pulse transitions at a second clocking pulse rate which is a multiple (preferably eight times (8×)) of the first clocking pulse rate, wherein the modified Manchester coded signal is modified by ON-OFF keying.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a refractive index profile selected to provide dispersion at 1550 nm of between −90 and −150 ps/nm/km; dispersion slope at 1550 nm of less than −1.5 ps/nm2/km; and kappa of between 40 and 95. The profile preferably has a core surrounded by a cladding layer of refractive index &Dgr;c, and at least three radially adjacent regions including a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2, and an annular ring region having a refractive index &Dgr;3, wherein &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2.

Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, provided on the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is 0.30% or more but 0.50% or less, and the relative refractive index difference of the inner cladding with respect to the outer cladding is −0.50% or more but −0.02% or less. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective area of 70 &mgr;m2 or more at the wavelength of 1.55 &mgr;m.

Abstract: A digital electrical signal Vin for transmission is supplied to a transistor Q12, a current compensation circuit 11, and a signal current source 13 to be band-compensated for generating a signal current I0. A predetermined current Id for a constant-current source 14 is subtracted from the signal current I0, and the result is an injection current Iin that drives an LED 15. The current Id is adjusted so that the injection current Iin becomes 0 at the low level. Thus, a signal-to-noise (S/N) ratio in waveform of light outputted from the LED 15 can be improved. Accordingly, the S/N ratio of the transmitted signal can be improved with band compensation.

Abstract: An optical telecommunication module capable of increasing the bandwidth and decreasing the RF return loss, comprising: a stem in which a laser diode and a photo-detector are disposed; a cap for protecting the laser diode and the photo-detector in the stem, the cap including a window formed on an upper part thereof; a common lead electrically connected to both the laser diode and the photo-detector; first and second leads electrically connected to the laser diode and the photo-detector, respectively; a dummy lead being electrically floated; and, a compensation element connected between the first lead and the dummy lead, wherein the compensation element having a predetermined resistance component and a predetermined inductance component.

Abstract: A method of fabricating a band-processing optical fibre filter having a center wavelength &lgr;0′, the method comprises (i) radius-reducing a mismatched multi-core optical fibre having a core phase matching wavelength (before radius reduction) of &lgr;0 and a radius (before radius reduction) of a0, to a reduced radius Ra0, where R=&lgr;0′/&lgr;0; and (ii) providing light input and output connections to a section of the radius-reduced multi-core fibre so that input light is launched into one of the cores of the multi-core fibre section and output light emerges from one of the cores of the multi-core fibre section.

Abstract: Information and control are synchronized as they flow through a large distributed IP router system with independent clocks. The IP router includes multiple equipment racks and shelves, each containing multiple modules. The IP router is based on a passive switching device, which in some embodiments is an optical switch. Control and data come to the switching device from different sources, which have different clocks. Timing and synchronization control are provided, such that information and control both arrive at the switching device at the proper time. A single point in the system originates timing, which is then distributed through various ASICs of the system to deliver configuration control to the switch at the appropriate time. The launch of information to the switch is also controlled with a dynamic feedback loop from an optical switch controller. Control aspects of the optical switch are aligned by this same mechanism to deliver control and data to the optical switch simultaneously.

Abstract: The invention provides an optical isolator including a light collector for redirecting and/or absorbing backward propagating radiation. In the preferred embodiment, the light collector includes at least one of a light absorbing material and a light redirector that does not interfere with forward propagating radiation, but collects the unwanted backward propagating light. Accordingly, the light collecting means are suitable for high power applications for protecting the input optics, including epoxy used to secure the input optical fiber, from unwanted reflected light. Some examples of appropriate light collecting means include neutral density filters, polarizers, mirrors, and right angle prisms.

Abstract: The present invention relates to a technology of an IP node for transferring IP packets accommodated in a wavelength division multiplexing optical signal.

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving ends of one, or more than one, of a plurality of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.