48 results about "Optical phase conjugation" patented technology

Iterating an optical phase conjugation of ultrasonically-modulated diffuse light emitted by a scattering medium includes illuminating the scattering medium with a light beam from a coherent light source, modulating the diffuse light transmitted through the scattering medium with an ultrasonic wave focused on a region of interest within the scattering medium, fixing a hologram, retro-reflectively illuminating the scattering medium using a phase-conjugated copy of the diffuse light that was ultrasonically modulated, moving the ultrasonic focus, and iterating until light is focused on the final target.

A system and method for focusing electromagnetic energy on a moving target. Generally, the inventive system sends a pilot beam to a target and analyzes a return wavefront to ascertain data with respect to any distortions and other phase and/or amplitude information in the wavefront. This information is then used to pre-distort an output beam by so that it is focused on the target by the intervening distortions. In an illustrative embodiment, the pilot beam is provided by a beacon laser mounted off-axis with respect to the output beam. The reflected wavefront is received through a gimbaled telescope. Energy received by the telescope is detected and processed to ascertain wavefront aberrations therein. This data is used to predistort a deformable mirror to create an output beam which is the phase conjugate of the received wavefront. In a first alternative embodiment, a nonlinear optical phase-conjugate mirror is employed to generate the required wavefront-reversed replica of the received wavefront. The system further includes an arrangement for modulating the output beam to confuse the target. In a second alternative embodiment, the system is adapted to examine atmospheric distortions of starlight to predistort the output beam. The alternative embodiment offers a faster response time and a lower susceptibility to detection.

An optical communication system comprising means for modulating a plurality of light carriers and then performing frequency division multiplexing on the modulated light carriers to generate a frequency division multiplexed light, a first single-mode fiber for transmitting the frequency division multiplexed signal light, means for generating a frequency division multiplexed signal light corresponding to a phase conjugate wave of the transmitted frequency division multiplexed signal light, and a second single-mode fiber for transmitting the frequency division multiplexed phase conjugate light. In the disclosed optical communication system, appropriate setting of parameters such as a mean light intensity of each fiber permits to eliminate an effect of channel-to-channel crosstalk.

The invention provides a programmable optical component based on a scattering medium, an optical field regulation system, and an optical field regulation method, and solves technical problems that a conventional optical component has single function, is high in optical wave modulation cost, has complex apparatus and low integration degree. The system in the invention is successively provided with a light source beam expanding module, a modulation module, a scattering medium microscopic module and a detection module, a data processing module arranged between the modulation module and the detection module. A computer circularly controls a space light modulator to modulate an input optical field, and a detector detects an output optical field; then data shaping is carried out and an optical transmission matrix of the scattering medium is detected; and then a programmable optical component is constructed so as to achieve optical field regulation with methods such as optical phase conjugation, phase retrieval, speckle reconstruction and the like, wherein the optical field regulation includes imaging, chromatic dispersion, abnormal chromatic dispersion, focusing, shaping, etc. The programmable optical component and the system are intelligent, multi-functional, low-cost, easy to operate, highly integrated and strong in operability, and can be applied to the scientific research fields such as military science, bio-medicines, integrated optic, nano photonics, etc.

A method and system for using optical phase conjugation in an optical communications network including an add-drop multiplexer. The method includes determining a position for an optical phase conjugator such that channel quality for a channel in improved above a threshold. Transmission characteristics such as amplifier launch power or dispersion features may be adjusted to compliment the optical phase conjugation. An alternate method includes positioning the optical phase conjugator to improve a weighted average channel quality for the network.

The invention provides a system for improving the laser collimation precision by utilizing an optical phase conjugation principle, comprising a laser device, wherein a polarizer, a beam expanding and collimation system, a first beam splitter, a first polarization spectroscope and a reflector are sequentially arranged along an emitting light beam of the laser device; a position detector is arranged in a beam splitting direction of the first beam splitter; reflection light of the reflector is parallel to the emitting light beam of the laser device; a second polarization spectroscope, a Faraday rotator, a second beam splitter and a space optical phase modulating device are sequentially arranged on the reflection light of the reflector; a wave-front detector is arranged in the beam splitting direction of the second beam splitter; and the space optical phase modulating device and the wave-front detector are connected to a computer. The invention further provides a method for improving the laser collimation precision by utilizing the system; the system disclosed by the invention has a simple structure and influences of uneven atmosphere on the laser collimation can be effectively compensated; and the space optical phase modulating device is used as a phase conjugation mirror so that the system has the advantages of small size, easiness for controlling and the like.

Disclosed is a microwave signal long distance optical fiber stationary phase transmission device based on optical phase conjugation. The microwave signal long distance optical fiber stationary phase transmission device based on the optical phase conjugation comprises an emitting end, a receiving end and a single mode optical fiber, wherein the emitting end is connected with the receiving end through the single mode optical fiber. The microwave signal long distance optical fiber stationary phase transmission device based on the optical phase conjugation only processes a signal at the emitting end, is low in construction and maintenance cost, reduces usage frequency of a frequency mixer, performs pre-distortion of a microwave signal mainly on light, improves the bandwidth of a system, only uses a microwave source, and does not need synchronization.

A device and method for performing fluorescence imaging with digitally time reversed ultrasound encoded light, using a source of ultrasound waves, a coherent light source, a digital optical phase conjugation (DOPC) device comprising a camera and a spatial light modulator (SLM), a detector of fluorescence, and one or more computers, to obtain an output that at least approximates an interaction between a complete time reversed field, of all of the encoded light's fields, and the scattering medium.

An optical fiber communication system according to the present invention has, for example, first and second phase conjugators. The first phase conjugator converts a signal beam from a first optical fiber into a first phase conjugate beam. The first phase conjugate beam is supplied to the second phase conjugator by a second optical fiber. The second phase conjugator converts the first phase conjugate beam into a second phase conjugate beam. The second phase conjugate beam is transmitted by a third optical fiber. The second optical fiber is composed of a first portion located between the first phase conjugator and a system midpoint and a second portion located between the system midpoint and the second phase conjugator. The total dispersion of the first optical fiber substantially coincides with the total dispersion of the first portion, and the total dispersion of the second portion substantially coincides with the total dispersion of the third optical fiber. By the construction, waveform distortion by chromatic dispersion or nonlinearity is compensated for.

A long haul transmission system uses a digital signal processor DSP instead of an additional optical phase conjugate copier because the optical phase conjugate copier requires high quality optical carrier regeneration to recover the pump and optical PLL to maintain phase matching between signal and pump. Therefore, the use of DSP to process the signal and idler at receiver end greatly simplifies the system setup, increases the system stability and decreases the system cost.

An optical transmission system is provided. The system includes first and second lines of optical fiber, each line including first, second, and third optical fiber portions, and an optical phase conjugator optically coupling the first and second lines. The first and third optical fiber portions have a local dispersion of like sign to each other, and opposite to the sign of the second optical fiber portion.

The desirable effects of an optical phase conjugator are accompanied by a frequency shift with reversal of the frequency order of channels in a multichannel optical communication system. Such effects are rectifiable by employing a sequence involving demultiplexing the multichannel signal, operating on the individual, demultiplexed channel with a corresponding optical phase conjugator or frequency shifter followed by multiplexing the signal. This sequence is combined with a complementary operation—optical phase conjugator to complement a frequency shifting sequence or frequency shifting to complement an optical phase conjugating sequence.

In the absence of using any chromatic dispersion compensation technique, it may be difficult to detect the transmitted data over long distances at the receiving end. Embodiments utilize the optical phase conjugation (OPC) property in silicon waveguides to compensate chromatic dispersion effect in optical fibers.

An optical system and associated method enable near real time optical phase conjugation. In the method, a translucent medium is illuminated by a sample illumination beam. Light scattered by the medium is directed to an electronic image sensor while a reference beam is also directed to the electronic image sensor. The scattered light and the reference beam form an interference pattern at the electronic image sensor. A digital representation of the interference pattern is recorded using the electronic image sensor, and the characteristics of a conjugate of the sample beam are computed from the numerical representation. A conjugate beam having the computed characteristics is generated using a configurable optical element and directed back to the translucent medium. The generation of the conjugate beam may be accomplished using a spatial light modulator.

The invention provides a solid quality improving method based on in-cavity phase conjugate, and aims at solving problems that light beams of a solid state laser are severe in heat distortion and present active optical means are complex and expensive. The solid state laser with an optical phase conjugate cavity is provided, and solid laser of high light beam quality can be obtained. An output coupling mirror 1, a pumping source 2, a solid gain medium 3, a Brillouin medium 4 and a back cavity mirror 5 are included; and a linewidth narrowing device can be included. The back cavity mirror and the output coupling mirror form a homocentric or confocal cavity, so that the waist part of a basic-mode light beam is just positioned in the Brillouin scattering medium; and the solid gain media is located near to the output coupling mirror as possible. When work is started, the back cavity mirror starts oscillation; and after that the power density reaches a stimulated Brillouin scattering threshold, the Brillouin medium and the output coupling mirror form the cavity; and high-quality light beams are output.