1435 results about "Transmission fiber" patented technology

In one aspect, the invention relates to a probe. The probe includes a sheath, a flexible, bi-directionally rotatable, optical subsystem positioned within the sheath, the optical subsystem comprising a transmission fiber, the optical subsystem capable of transmitting and collecting light of a predetermined range of wavelengths along a first beam having a predetermined beam size. The probe also includes an ultrasound subsystem, the ultrasound subsystem positioned within the sheath and adapted to propagate energy of a predetermined range of frequencies along a second beam having a second predetermined beam size, wherein a portion of the first and second beams overlap a region during a scan.

Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

The Fibre. Channel standard was created by the American National Standard for Information Systems (ANSI) X3T11 task group to define a serial I / O channel for interconnecting a number of heterogeneous peripheral devices to computer systems as well as interconnecting the computer systems themselves through optical fiber and copper media at gigabit speeds (i.e., one billion bits per second). Multiple protocols such as SCSI (Small Computer Serial Interface), IP (Internet Protocol), HIPPI, ATM (Asynchronous Transfer Mode) among others can concurrently utilize the same media when mapped over Fibre Channel. A Fibre Channel Fabric is an entity which transmits Fibre Channel frames between connected Node Ports. The Fibre Channel fabric routes the frames based on the destination address as well as other information embedded in the Fibre Channel frame header. Node Ports are attached to the Fibre Channel Fabric through links.

A method of transporting a packet oriented client signal which uses a buffer-to-buffer flow control mechanism over a synchronous transmission network by assigning an arbitrary synchronous payload, where the synchronous payload bandwidth may be significantly smaller than the full bandwidth of the client signal. Flow control over the synchronous network is provided by the buffer-to-buffer flow control mechanism of the client signal to automatically regulate the data throughput to ensure no data can be lost. The method is independent of the Client Signal Data Rate and the provisioned SDH / SONET bandwidth, and SDH / SONET payload which may be non-concatenated, contiguously concatenated, or virtually concatenated. In particular, the method may be used to support the transport of Fibre Channel (1G, 2G and 4G), and ESCON (200M) in a synchronous payload.

In one form of the present invention, there is provided a fiber optic communication system comprising: an optical signal source adapted to receive a base binary signal and produce a first signal, said first signal being frequency modulated; and an optical spectrum reshaper adapted to reshape the first signal into a second signal, said second signal being amplitude modulated and frequency modulated; characterized in that: the frequency characteristics of said first signal, and the optical characteristics of said optical spectrum reshaper, being such that the frequency characteristics of said second signal are configured so as to increase the tolerance of the second signal to dispersion in a transmission fiber. In another form of the present invention, there is provided an optical transmitter comprising: a frequency modulated source for generating a first frequency modulated signal, and an amplitude modulator for receiving the first frequency modulated signal and for generating a second amplitude and frequency modulated signal. In another form of the present invention, there is provided a method for transmitting an optical signal through a transmission fiber comprising: receiving a base binary signal; operating an optical signal source using the base binary signal to produce a first signal, said first signal being frequency modulated; passing the frequency modulated signal through an optical spectrum reshaper so as to reshape the first signal into a second signal, said second signal being amplitude modulated and frequency modulated; the frequency characteristics of said first signal, and the optical characteristics of said optical spectrum reshaper, being such that the frequency characteristics of said second signal are configured so as to increase the tolerance of the second signal to dispersion in a transmission fiber; and passing the second signal through a transmission fiber. In another form of the present invention, there is provided a method for transmitting a base signal, comprising: using the base signal to produce a frequency modulated signal; and providing an amplitude modulator for receiving the frequency modulated signal and for generating an amplitude and frequency modulated signal.

The system and method of the present invention relates to using spectroscopy, for example, Raman spectroscopic methods for diagnosis of tissue conditions such as vascular disease or cancer. In accordance with a preferred embodiment of the present invention, a system for measuring tissue includes a fiber optic probe having a proximal end, a distal end, and a diameter of 2 mm or less. This small diameter allows the system to be used for the diagnosis of coronary artery disease or other small lumens or soft tissue with minimal trauma. A delivery optical fiber is included in the probe coupled at the proximal end to a light source. A filter for the delivery fibers is included at the distal end. The system includes a collection optical fiber (or fibers) in the probe that collects Raman scattered radiation from tissue, the collection optical fiber is coupled at the proximal end to a detector. A second filter is disposed at the distal end of the collection fibers. An optical lens system is disposed at the distal end of the probe including a delivery waveguide coupled to the delivery fiber, a collection waveguide coupled to the collection fiber and a lens.

A bend-loss tolerant multimode fiber transmission system is provided. The system includes: a transmission fiber having a core and a cladding, and a mode-launching system for selectively exciting only a useful portion of the transmission modes, that portion corresponding to high effective refractive indices relative to a refractive index of the cladding the useful portion corresponding to a substantial number of modes. The mode-launching system may include a lead-in fiber, coupled to the transmission fiber, supporting a number of lead-in modes substantially corresponding to the number of transmission modes in the useful portion. The transmission fiber may have a refractive index profile, within a region of its core that is aligned with the lead-in fiber core, which has a shape that matches a refractive index profile shape in the lead-in fiber core. The transmission fiber core may have a graded refractive index profile that is parabolic or nearly parabolic or truncated.

Systems and methods for transmitting quantum and classical signals over an optical network are disclosed, wherein the quantum signal wavelength either falls within the classical signal wavelength band, or is very close to one of the classical signal wavelengths. The system includes a deep-notch optical filter with a blocking bandwidth that includes the quantum signal wavelength but not any of the classical signal wavelengths. The deep-notch optical filtering is applied to the classical signals prior to their being multiplexed with the quantum signals to prevent noise generated by the classical signals from adversely affecting transmission of quantum signals in the transmission optical fiber. Narrow-band filtering is also applied to the quantum signals prior to their detection in order to substantially exclude spurious non-quantum-signal wavelengths that arise from non-linear effects in the optical fiber. The present invention allows for the quantum and classical signals to have wavelengths within just a few nanometers of one another, which has benefits for both classical and quantum signal transmission on a common transmission optical fiber.

Apparatus for optically pumping a clad amplifier fiber includes one or more transmission fibers arranged and configured to insert pump-light from a pump light source such as a diode-laser into the cladding of the amplifier fiber. The pump light propagates through the cladding and a portion of the pump light is absorbed in the doped core of the amplifier fiber. At least one of the transmission fibers is arranged to receive an unabsorbed portion of the propagated pump light from the amplifier cladding and re-insert the unabsorbed portion of the pump-light into the cladding for re-propagation through the cladding. This provides that pump light that would otherwise be wasted is circulated through the amplifier fiber for further absorption by the amplifier core.

An electronic endoscope comprises a housing and a flexible tube. A light-transmitting optic fiber and a light-receiving optic fiber are provided in the flexible tube. A light source and an imaging device are provided in the housing. The light source outputs a pulsed distance-measuring light beam, which is transmitted along the light-transmitting optic fiber, and irradiated to a subject. A reflected light beam generated by the subject due to the distance-measuring light beam is transmitted along the light-receiving optic fiber, to enter the imaging device, in which an electric charge corresponding to the subject image (i.e., an image signal of a three-dimensional image) is accumulated. A timing of the accumulating operation of the imaging device is delayed depending on the lengths of the fibers.

Described is an optical fiber system for delivering ultrashort pulses with minimal distortions due to nonlinearity. The system is based on delivering the optical pulses in a higher order mode (HOM) of a few-moded fiber. The fiber is designed so that the dispersion for the HOM is very large. This results in a dispersion length LD for the delivery fiber that is exceptionally small, preferably less than the non-linear length LNL. Under these conditions the system may be designed so the optical pulses experience minimum non-linear impairment, and short pulse / high peak power levels are reproduced at the output of the delivery fiber.

Endoscopic system 40 comprises composite optical fiber 34 that consists of a large-diameter, laser light transmitting optical fiber surrounded by a large number of image transmitting fibers that are bundled together to form an integral assembly with the central fiber, laser applying and image observing optical unit 42 that is connected to the eyepiece portion of said composite optical fiber such that it launches laser light into said large-diameter optical fiber and that the image being transmitted through said image transmitting optical fiber is focused on a camera to become observable, and an illuminating light transmitting unit that transmits illuminating light to the tip of the objective portion of said composite optical fiber for irradiation purposes.

An optical connector having a plurality of directional taps and connecting between a plurality of optical waveguides (e.g., such as a connector between a waveguide that is part of, or leads from, a seed laser and / or an initial optical-gain-fiber power amplifier, and a waveguide that is part of, or leads to, an output optical-gain-fiber power amplifier and / or a delivery fiber), wherein one of the directional taps extracts a small amount of the forward-traveling optical output signal from the seed laser or initial power amplifier (wherein this forward-tapped signal is optionally monitored using a sensor for the forward-tapped signal), and wherein another of the directional taps extracts at least some of any backward-traveling optical signal that may have been reflected (wherein this backward-tapped signal is optionally monitored using a sensor for the backward-tapped signal).

A hub for use in a passive optical network (PON) includes a transmission fiber on which an information-bearing optical signal is received, a double-cladded, rare-earth doped fiber located along the transmission fiber for imparting gain to the information-bearing optical signal, and a combiner having an output coupled to the transmission fiber and a plurality of inputs. The output is coupled to the transmission fiber such that optical energy at pump energy wavelengths but not signal wavelengths are communicated therebetween. At least one pump source is optically coupled to one of the inputs of the combiner for providing optical pump energy to the double-cladded, rare-earth doped fiber. An optical splitter is also provided. The optical splitter has an input coupled to the transmission fiber for receiving an amplified, information-bearing optical signal and a plurality of outputs for directing portions of the amplified, information-bearing optical signal to remote nodes in the PON.

The present invention is to provide an optical fiber preform suitable for the production of an energy-transmitting or ultraviolet light-transmitting optical fiber, which has an excellent transmittance of a high-energy light of 50 KW / cm2 or more in terms of laser peak power or an ultraviolet light, to be transmitted through the optical fiber and which exhibits excellent durability that causes almost no deterioration by the irradiation with those two lights; and a production process thereof. The present invention relates to an energy-transmitting or ultraviolet light-transmitting optical fiber preform, having a core and a cladding each comprising a silica glass, wherein the core has an average OH concentration of 0 to 10 ppm, an average O2 concentration of ≦1015 molecules / cm3, an average ODC (I) concentration of ≦1013 defects / cm3, an average ODC (II) concentration of ≦1012 defects / cm3 and an average F concentration of ≦1,000 ppm, and the cladding has an average OH concentration of 0 to 10 ppm, an average F concentration of ≧7,000 ppm, an average O2 concentration of ≦1016 molecules / cm3, an average ODC (I) concentration of ≦1013 defects / cm3 and an average ODC (II) concentration of ≦1012 defects / cm3.

Apparatus and method for distributed absorption of pump light over a length of delivery fiber that is, for example in some embodiments, fusion spliced to an end of a multiply clad gain fiber that has significant unused pump light at the end of the gain fiber. In some embodiments, this includes coupling a fiber amplifier to a passive-core delivery fiber that includes a distributed pump dump. In some embodiments, at an output end of the amplifying fiber there is still a significant amount of pump power. If all this pump power is dumped in one small place (e.g., at a splice between the amplifying fiber and a passive delivery fiber) a hot spot will result, leading to unreliable devices that fail (have catastrophic changes in operating performance). The present invention provides a distributed pump dump built into a delivery fiber that is passive to the signal in its core.

The present invention relates to a transmission optical fiber. The optical fiber includes, from its center to its periphery a central core, an intermediate cladding, and a depressed cladding. The optical fiber has an effective area (Seff) of at least about 120 μm2 at a wavelength of 1550 nm and an effective cutoff wavelength (λCeff) of less than 1600 nm. The optical fiber has an effective area of more than 120 μm2 with a cutoff wavelength limited to less than about 1600 nm without degradation of other optical parameters (e.g., attenuation losses and dispersion).

A fiber optic probe and optical coupler assembly, and methods for making the assembly and reproducibly aligning a plurality of optical fibers therein. The coupler is used with a probe that includes a housing or probe body, a probe tip, at least one light-transmitting fiber, at least one light-receiving fiber spaced apart from the light-transmitting fiber, and (if desired), in-line devices such as filters and lenses positioned in optical communication with the fibers. The coupler includes at least one aligning pin that helps maintain the transmitting and receiving fibers in precise, reproducible relative alignment therein; thus, the coupler can be cut to install filters and other in-line devices, then readily re-assembled for use with the cut ends precisely and accurately realigned. The coupler is simple and rugged, and can be manufactured and assembled without the need for high-precision machining or optical alignment procedures.

An optical transmission and amplification system includes a multichannel transmission span with a length of a multicore transmission fiber having a plurality of individual transmission cores. A first tapered multicore coupler provides connectivity between the plurality of transmission cores of the multicore fiber and a respective plurality of individual transmission leads. A fiber amplifier is provided having a plurality of individual cores including at least one pump core and a plurality of amplifier core. A second tapered multicore coupler provides connectivity between the amplifier cores of the fiber amplifier and a respective plurality of amplifier leads, and between the at least one pump core and a respective pump lead.

In one aspect, the invention relates to a probe. The probe includes a sheath, a flexible, bi-directionally rotatable, optical subsystem positioned within the sheath, the optical subsystem comprising a transmission fiber, the optical subsystem capable of transmitting and collecting light of a predetermined range of wavelengths along a first beam having a predetermined beam size. The probe also includes an ultrasound subsystem, the ultrasound subsystem positioned within the sheath and adapted to propagate energy of a predetermined range of frequencies along a second beam having a second predetermined beam size, wherein a portion of the first and second beams overlap a region during a scan.

A dispersion compensation controlling apparatus used in a very high-speed optical communication system adopting optical time division multiplexing system comprises a first specific frequency component detecting unit (2a) detecting a first specific frequency component in a baseband spectrum in a transmission optical signal inputted to a receiving side over a transmission fiber as a transmission line (6a), a first intensity detecting unit (3a) detecting information on an intensity of the first specific frequency component detected by the first specific frequency component detecting unit (2a), and a polarization-mode dispersion controlling unit (220a) controlling a polarization-mode dispersion quantity of the transmission line (6a) such that the intensity of the first specific frequency component detected by the first intensity detecting unit (3a) becomes the maximum, thereby easily detecting and compensating polarization-mode dispersion generated in a high-speed optical signal.

A optical fiber gas sensor employs a optical fiber Fabry-Perot interferometer constituting a low reflection cavity lens and a measurement optical fiber to detect sound pressure wave signal generated by gas after absorbing light energy, and a realization method for optical acoustic gas sense technique is provided. Pulse modulated excited light is emitted by an excitation light source, passes through a band-pass filter and enters a gas cavity from a gas cavity window; the excited light emitted into the gas cavity generates a sound pressure wave which strength corresponds to measured gas concentration in the gas cavity after absorbing by the measured gas; the sound pressure wave is transmitted to vibration of a vibrating film sheet by the vibrating film sheet which is equipped at other end of the gas cavity; a measuring light signal emitted by measuring light source driven by a first drive power supply passes through a optical fiber wave combination equipment, a transmission optical fiber and a optical fiber wave separation equipment and enters a measuring optical fiber of the Fabry-Perot interferometer; concentration value of the measured gas is obtained by optical path difference of the return light beam and the light beam directly reflected by an optical end face.