1961 results about "All optical" patented technology

Disclosed is an all-optical frequency upconverter in a radio-over-fiber system that outputs upconverted optical radio frequency (RF) signals using an optical intermediate frequency signal and an optical local oscillation signal. The all-optical frequency upconverter includes a semiconductor optical amplifier that mixes the optical intermediate frequency signal with the optical local oscillation signal through four wave mixing, and an optical filter that filters a plurality of frequency component signals, which are generated through the four wave mixing, to extract optical RF signals. According to the invention the system configuration can be made simple, and wide LO and IF frequency bandwidths can be provided.

An imaging system and method are presented. The system comprises an imaging lens unit, an imaging detector, and a birefringent element located between the imaging lens unit and the imaging detector. The system is thus configure and operable to provide in-focus imaging of objects located at both near-field and far-field ranges. Also provided is an optical device configured to be mounted on an imaging lens, being one of the following: a lens of an individual's glasses, on a contact lens, and an eye internal lens. The optical device is configured to be located between the imaging lens and the retina and comprises a birefringent element, to thereby provide in-focus imaging onto the retina of the objects located at both near-field and far-field ranges therefrom.

An exit pupil extender with one input optical element and two exit optical elements disposed on different sides of the input optical element. The exit pupil extender also comprises two intermediate optical couplers, each disposed between the input optical element and one exit optical element. The couplers serve as exit pupil extending components. All optical elements and couplers are diffractive optical elements having grating lines. The grating lines of one optical element are substantially parallel to that of other optical elements, but the grating lines of the couplers are at substantially a 60-degree angle from that of the optical elements in order to optimize the exit pupil extending efficiency.

Loss of optical signal is detected in a synchronous communications system by detecting features of a monitor signal occurring at a detection frequency corresponding to the frame rate. Since the frame rate is substantially less than the bit rate, monitoring and detection can be performed at a lower bandwidth than the bit rate. An auto-correlation circuit utilises delays which are an integral multiple of the frame rate and produces a detection value which is compared with a threshold value. Alternatively, detection may be based on a power measurement of a band pass filtered monitor signal by setting the lower bandwidth limit above zero frequency and normalizing the measurement of power relative to an average power measurement. A loss of signal may then be detected by a change in power measurement relative to a threshold and can be used for asynchronous systems as well as synchronous systems. Loss of signal detection may be utilised to control an optical switch to re-route optical signals and generate alarm signals. The use of such detection in all optical networks avoids the requirement for electronic processing at the bit rate as a means of detection of loss of signal.

The invention provides a unified optical network architecture for metro and access communication networks, wherein a metro ring network interfaces access PONs through one or more reconfigurable Optical Add/Drop Multiplexers to provide wavelength-reconfigurable all-optical transmission of communication signals from the metro ring network to designated optical network units associated with the end-users, and wherein one metro hub located in the metro ring network is utilized to set transmission wavelengths and timing for both downstream and upstream signal transmission for multiple access PONs.

According to exemplary embodiments of the present disclosure, it is possible to provide method, system, arrangement, computer-accessible medium and device to stimulate individual neurons in brain slices in any arbitrary spatio-temporal pattern, using two-photon uncaging of photo-sensitive compounds such as MNI-glutamate and/or RuBi-Glutamate with beam multiplexing. Such exemplary method and device can have single-cell and three-dimensional precision. For example, by sequentially stimulating up to a thousand potential presynaptic neurons, it is possible to generate detailed functional maps of inputs to a cell. In addition, it is possible to combine this exemplary approach with two-photon calcium imaging in an all-optical method to image and manipulate circuit activity. Further exemplary embodiments of the present disclosure can include a light-weight, compact portable device providing for uses in a wide variety of applications.

A polarization independent (PI) interferometer design that can be built from standard optical components is described. Based upon a Michelson interferometer, the PI interferometer uses a 50/50 splitter and Faraday Rotator Mirrors (FM's). The interferometer achieves good optical characteristics, such as high extinction ratio (ER) and low insertion loss (IL). Lack of polarization sensitivity reduces interferometer construction tolerances and cost, enhances performance and utility, and expands the scope of interferometric based devices. Such characteristics can be used to construct flexible, high performance, polarization insensitive, multi-rate, self-calibrating, optical DPSK receivers, power combiners, optical filters and interleavers, all-optical switches, and cascaded interferometers. Since polarization is not maintained in standard fiber optic networks, a PI-DPSK receiver allows for use of more sensitive DPSK communications over fiber, without need for costly polarization control hardware. Other applications of PI interferometers include optical CDMA, secure communications, optical coherence tomography (OCT), and temporal gratings with ultra-precise timing.

A bistable photonic crystal configuration comprises a waveguide sided coupled to a single-mode cavity. This configuration can generate extremely high contrast between the bistable states in its transmission with low input power. All-optical switching action is also achieved in a nonlinear photonic crystal cross-waveguide geometry, in which the transmission of a signal can be reversibly switched on and off by a control input, or irreversibly switched, depending on the input power level.

An optoelectronic device having a flexible substrate and an optical interconnect (i.e. waveguide) comprising a sol-gel based material formed on the substrate. The sol-gel based waveguide is capable of being integrated into an all-optical system and provides for greater interconnect distance and lower signal loss. Other sol-gel based optical devices, such as filters, optical source, detectors, sensors, switches and the like, will be implemented in conjunction with the sol-gel based waveguides to provide for an integrated optical system. Methods of formulating the sol-gel based material and methods for fabricating the sol-gel based devices are also provided.

Electronic components of an optoelectronic sensor for a measuring system are arranged on the side of a semiconductor substrate that is facing away from a scale. The semiconductor substrate between electronic components and the scale is removed at those locations where the components emit or detect an electromagnetic beam. In this way, it is possible to arrange all of the electrical connections of the components and further electronic assemblies of the measuring system on a first side of the semiconductor substrate, and all optical components of the measuring system on a second side of the semiconductor substrate.

A coal mine underground safety comprehensive monitoring system based on fiber grating sensors and belongs to a coal mine underground safety monitoring system. The system comprises an aboveground part and an underground part; the aboveground part comprises a static fiber grating demodulator, a computer data processing system, a printer, a server and a client; the underground part comprises an optical switch array, a working face safety monitoring subsystem and a laneway safety monitoring subsystem; each of the two monitoring subsystems at least comprises a monitoring base station; each monitoring base station at least comprises a survey station; each survey station is corresponding to one group of fiber grating sensors; the advantage is that the system adopts multiple survey stations to perform underground multi-parameter monitoring, integrates the fiber grating sensors, adopts all-optical survey and optical fibers for signal transmission, is intrinsically safe, has high anti-electromagnetic interference capability and a good monitoring effect, realizes real-time continuous long-term on-line monitoring and the sharing of data in an entire mining area to better guide the safety production of a coal mine, can effectively reduce safety accidents of the coal mine and realizes safe and efficient production of the coal mine.

Optical networking has become ubiquitous in providing low cost, high speed communications networks supporting our communication needs from FTTH through long haul to undersea. The large number of users and high speeds provided to each user fiber mean that information retrieval and routing functionality within the data centers hosting this information can become the bottleneck both in terms of speed and latency. According to embodiments of the invention the inventors present architectures based upon all-optical passive optical networks that support a distributive approach to latency reduction as well as protocols relating to their deployment. Beneficially, such POCXN concepts exploit optical components already supported by high volume manufacturing techniques as well as CWDM/DWDM techniques for throughput increase.

A method and apparatus for all optical orthogonal frequency division multiplexing (OFDM) employing Inverse Fast Fourier Transform/Fast Fourier Transform by integrated coupler interferometrically.

This invention relates to the design of a scaleable high performance multiservice network based on programmable transport. A meshed network with dynamically-adjustable link capacities and nodes which provide data packing into "containers" for transport is proposed. A ring-based network, exchanging data containers among its nodes, is the preferred implementation, due to its flexibility, maintainability, and high reliability. With lossless rings, the quality of service is controlled solely by the origin and destination nodes, without any interference from other data streams. Flexible programmable transport greatly improves the performance, simplifies the controls, and facilitates scaleability. The concept is a departure from classical network thinking. By reducing the complexity of the network core, an economical, reliable, and manageable network with feature-rich edge nodes can be realized. An architecture with recursive ring-based structures provides a high degree of flexibility in bandwidth allocation and is compatible with current transport networks and future all-optical networks.

The invention involves an image sensor camera module and a method of fabricating the image sensor camera module. The image sensor camera module uses a single-body type lens holder defined by a hollow cylindrical body having a shoulder protruding radially inwardly from an inner surface thereof. First and second lenses therein are spaced apart by a first spacer and a filter therein is spaced from the second lens by a second spacer. An image sensor is adhered to a lower rim of the body, and the filter is adhered to an upper rim thereof. All optical elements within the lens holder thus are affixed in fixed relative position compatible with a predefined focal length and axis. Moreover, the adhesively sealed interior of the body of the image sensor camera module prevents particulate contamination.

A wavelength converter incorporating an on-chip integrated laser for use in an optical system. The converter includes a first port for receiving an optical input signal such as a WDM signal and providing it to an interferometer, and an output port for outputting a signal which is a wavelength-converted version of the input signal. An optical source or laser is fabricated on the chip substrate on which the interferometer is formed for providing operating power to the interferometer. Power levels of the input signal are maintained by adjusting an on-chip semiconductor optical amplifier that receives the optical input signal and provides the amplified signal to the interferometer. In an alternative embodiment, the on-chip optical source is replaced by an on-chip pre-amplifier for an external laser source.

In all-optical networks, optical switching and routing become the most important issues for interconnecting the transport network layers. This invention describes a novel tunable optical add/drop filter for the all-optical wavelength-division-multiplexing (WDM) network applications. This filter can add or drop part of the high transmission capacity signals of a WDM link. It can be used to decentralized access point in the access network or as small core network node to realizing branching points in the network topology. It works in both wavelength and space domains. It has the advantages of: 1) High throughput and low voltage operation; 2) Wide tuning range and therefore, high channel capacity; 3) High isolation and high directivity between input and output ports; 4) Compact device packaging is possible as compares to the conventional grating and mechanical switching type of add/drop filter; 5) Multiple ports add/drop tunable filters can be realized with this invention to interconnect multiple WDM networks. This novel add/drop filter can be used in various WDM topologies. It enhances the performance of the conventional tunable filter by re-routing the rejected wavelengths back to network, which not only save the precious optical energy, but also cut down the return loss of the device.

These and other objects of the present invention are achieved in a method of transmitting optical signal traffic. An all optical network is provided with at least two rings that are geographically dispersed. Each ring includes at least one transmitter and at least one receiver. The available wavelengths are separated into distinct ring bands. The optical signal traffic is shared throughout the entire optical network. Each ring is provided with its own distinct ring band of the optical signal traffic. All of the optical signal traffic is transmittable throughout the optical network. Each receiver is configured to receive only wavelengths in a ring band designated for its associated ring.

The invention discloses an all-optical true random number generator, which comprises an all-optical true random number entropy source, wherein the all-optical true random number entropy source injects output light of a continuous laser device I into a two-section semiconductor laser device through a 3dB optical fiber coupler I and a light attenuator, produces a high-speed chaos self-pulse signal and controls the repeated frequency of the chaos self-pulse signal by adjusting the light injection intensity and the frequency detuning amount. Sampling and subsequent processing are not required; the additional problem caused by signal distortion because of sampling in the prior art is solved; the complexity of a system is greatly reduced; a code rate can be tuned in a large range by changing the light injection intensity and the frequency detuning amount; and the code rate is up to Gbps and can be directly compatible with a light network.