439 results about "Optical delay line" patented technology

An optical coherence tomography (OCT) system including an interferometer provides illuminating light along a first optical path to a sample and an optical delay line and collects light from the sample along a second optical path remitted at several scattering angles to a detector. In one embodiment, illuminating light is directed along a number of incident light paths through a focusing lens to a sample. The light paths and focusing lens are related to the sample and to both the incident light source and the detector. In another embodiment, a focusing system directs light to a location in the sample. A transmission grating or acousto-optic modulator directs light from the sample at an angle representative of the wavelength of the incident light on the transmission grating or acousto-optic modulator.

In one embodiment, the invention relates to an apparatus for increasing the repetition rate in a light source. The apparatus includes a first optical coupler comprising a first arm, a second arm and a third arm; a first mirror in optical communication with the second arm of the first optical coupler; and a first optical delay line having a first end in optical communication with the third arm of the first optical coupler and a second end in optical communication with a second mirror, wherein light entering the first arm of the first optical coupler leaves the first arm of the first optical coupler either delayed by an amount (τ) or substantially undelayed.

Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

The biggest bottleneck in the Internet today is caused by the slow speed of routers, compared to the speeds that are achieved by optic fibers with DWDM (Dense Wave Division Multiplexing). Packet switching or something similar to it is needed not just for better utilization of the lines, but also because it is superior to circuit switching in many ways, such as better scalability as the Internet grows, better handling of traffic congestions, and better routing flexibility. But optical routers are currently unable to do packet switching except by translating the data to electronic data and then back, which is very inefficient. The present invention solves this problem by optically marking and detecting the packet headers or parts of them, translating at most only the headers or parts of them to electronics for making packet switching decisions, and keeping the rest of the packets in optical delay lines, and solving response-time problems in the router, so that the crude optical switches can execute the packet switching decisions at fast bit rates. This solution has very high scalability and becomes even more efficient when physical addresses are used. Another optimization described in this invention is improving routing efficiency and bandwidth utilization by grouping together identical data packets from the same source going to the same general area with a multiple list of targets connected to each copy of the data and sent together to the general target area. These grouped packets are then preferably broken down into smaller groups by the routers in the general target area and finally broken down to individual data packets for delivering to the final actual destinations. This optimization works best with Physical addresses, and can be very useful for example for optimizing the access to very popular sites such as for example Yahoo or CNN, and can be used also for example for more efficiently transferring streaming data, such as for example from Internet radio stations, or Internet TV stations which will probably exist in the next years. Another important optimization is a new architecture and principles for routing based on physical geographical IP addresses (such as for example based on GPS), in a way much more efficient than has been previously discussed in the literature that suggested using physical (geographical) addresses. This is preferably based on a hierarchy similar to a hierarchical road system, so that preferably the MAIN routers (and/or intermediary-level routers) are preferably also connected directly and preferably with high-bandwidth as peers between each other, without having to go through lower-level routers in order to reach their peers, so that once a higher-level router (and especially if it's one of the MAIN routers) decides to forward a packet (or a group of packets) to a higher-level peer, preferably the packets don't have to go through lower level routers. However, conversion from the current architecture to the new one can be done very easy, as shown in the description below.

An active device for dynamic control of the transmission properties has at least one photonic crystal waveguide that has an electrically insulating layer formed within or near the waveguide core and two lateral conductive regions divided by the insulating layer. An alternating voltage signal induces phase and amplitude changes of electromagnetic wave propagating inside the device. Electromagnetic wave signals propagating through two such active photonic crystal waveguide devices may be mixed to produce at least one output signal through interference. Devices having one or more such active photonic crystal waveguides may be utilized as a tunable optical delay line, a tunable optical filter, a switch, or a modulator. A preferred embodiment comprises a photonic crystal waveguide made of a silicon slab with a periodic array of apertures or oxide columns therein, wherein an silicon oxide layer disposed in the waveguide core separates a p-doped region from an n-doped region.

The invention relates to a distributed optical fiber sensing system, and in particular relates to a chaos Brillouin optical coherence domain analysis distributed optical fiber sensing device and method. According to the invention, the problems of unavailable spatial resolution and sensing distance combination, severely limited sensing distance and low spatial resolution of the existing distributed optical fiber sensing system are solved. The chaos Brillouin optical coherence domain analysis distributed optical fiber sensing device comprises a wide spectrum chaos semiconductor laser, a 1*2 optical fiber coupler, an optical scrambler, an optical isolator, a first optical amplifier, a variable optical delay line, a second optical amplifier, an optical circulator, a sensing optical fiber, a tunable optical filter, a broadband gain photodetector, a data acquisition device, a signal processing device and a display device. The device and the method, which are provided by the invention, are applicable to the field of distributed optical fiber sensing.

The invention relates to a normal-temperature normal-pressure femto-second CARS (Coherent Anti-stokes Raman Spectroscopy) time-resolved spectrum measuring system which relates to the technical field of nonlinear optics and solves the problem of multiple limiting factors of traditional femto-second CARS time-resolved spectrum measuring experiment. Beams output by a femto-second laser are adjusted through a series of reflectors and optical delay lines by the system to form three bundles of beams which have approximate energy and are respectively positioned on three peaks of a square on the vertical direction of the beams, the beams are focused to a sample pool and then emit a new beam along a specific angle, i.e. a CARS signal, the CARS signal is filtered through a filter plate, then received by a probe and input to a monochromator, the data acquisition of an electrical signal converted by a photomultiplier is carried out by utilizing BOCCAR, and the data are input to a computer for data processing. The invention can carry out femto-second CARS time-resolved spectrum measurement under the experimental conditions of normal temperature and normal pressure and is applicable for the femto-second CARS spectrum measurement of gas samples and liquid samples in a static sample pool.

A variable optical delay line using MEMS devices. A reflector on a micro machine linear rack is positioned and spaced from an input source and/or an output to receive and reflect input light waves toward the output. The distance between the reflector and the input and output is variable and thereby enables selective path delay compensation of the input light wave signals. Other disclosed embodiments utilize pivoting MEMS mirrors and selective adjustment of the mirror pivot angles to provide the selective path delay compensation required in a light wave system.

A method of testing a Laser Detection and Ranging (LADAR) or LIght Detection And Ranging (LiDAR) system includes receiving an input signal from the LADAR/LiDAR and triggering light/laser sources to output pulses. The method includes transmitting the light/laser pulses into a first end of two or more fiber optical delay lines. The method includes transmitting the pulses throughout a length of two or more fiber optical delay lines. The method includes after a delay time corresponding to the length of the fiber optical delay lines, transmitting the pulses out through a second end of the fiber optical delay lines arranged within a target plane. The pulses output yield a return signals transmission from the target plane to the LADAR/LiDAR. The return signal transmission is delayed by times for the light/laser pulses to traverse the length of the fiber optical delay lines.

The present invention discloses an interferometer optical switch that can carry out switching over a broad band and has a high extinction ratio and large fabrication tolerance. The interferometer optical switch employs a phase generating coupler, the phase difference of the output of which has wavelength dependence, as at least one of the optical multi/demultiplexing device included in the interferometer optical switch. A wavelength insensitive interferometer optical switch is implemented by making the sum 2π{φ₁(λ)+φΔ_L(λ)+φ₂(λ)} constant regardless of the wavelength, where φ₁(λ) is the phase produced by the first optical multi/demultiplexing device, 2πφΔ_L(λ) is the phase difference of the optical delay line with an optical path length difference of ΔL, and 2πφ₂(λ) is the phase produced by the second optical multi/demultiplexing device.

An optical multi/demultiplexing circuit includes at least one phase generating optical coupler and an optical delay line coupled to the phase generating optical coupler. The phase generating optical coupler consists of at least one input and at least two outputs. At least one of the phase generating optical coupler has a wavelength dependent or frequency dependent output phase difference in the passband of the circuit so that it can change the transmittance characteristics of the optical multi/demultiplexing circuit.

The invention belongs to the technical field of optical communication devices and relates to a passive mode-locking fiber laser delay feedback chaotization system based on graphene, comprising a pumping laser (1), a wavelength division multiplexing fiber coupler (2), a first fiber coupler (3), a mode-locking device (9), an erbium-doped fiber (7), a polarization controller (5), an isolator (6), a second fiber coupler (4), a photodetector (10), an A/D conversion circuit (11), a single chip microcomputer (15), an RS 232 interface (16) and an optical delay line (12), wherein the optical delay line (12) receives control signals and carries out delay feedback to enable the whole system to be in a chaotization state, and the mode-locking device (9) is a graphene mode-locking device. The invention can generate a femto-second order optical pulse without an external modulation source, has the advantages of easy synchronization, high output pulse peak power, easy installation and operation and simple structure, and the like and can realize all-fiber integration and create the foundation of realizing chaotization synchronization and secrete communication.

The invention discloses real-time imaging skin diagnosis equipment by optical coherence tomography, and belongs to the field of optical imaging equipment. The equipment comprises a power supply, a light source control circuit, a light source, an indicating light source, a first optical fiber coupler, a second optical fiber coupler, an OCT probe, an optical delay line, a photo detector, a signal processing and control circuit, and a computation processing and display device. The imaging equipment takes the optical coherence tomography (OCT probe) as a core, processes signals rapidly by the signal processing and control circuit, and improves the imaging speed and image resolution by cooperating with the computation processing and display device; designs of a wideband light source and a duckbill-shaped probe applicable to skin scanning cause the equipment to be applicable to scanning human skin, and real-time and rapid imaging can be realized by cooperation of the signal processing and control circuit with the computation processing and display device.