42 results about "Nonlinear waveguide" patented technology

Electromagnetic radiation sources operating in the Terahertz (THz) region capable of overcoming the Manley-Rowe limits of known optical schemes by achieving phase matching between a THz wave and optical pulse in a nonlinear waveguide, or by achieving both phase and group velocity matching between a THz wave and optical pulse in a nonlinear waveguide to yield even higher efficiencies in converting optical power to the THz region.

The present invention relates to method for spectrally equalized frequency comb generation. In order to carry this method, the following steps are followed: seed laser or lasers are modulated to acquire frequency chirp necessary to enable temporal compression and an increase in peak optical intensity necessary for an efficient nonlinear optical mixing process to occur; the compressed waveform is reshaped by nonlinear-transfer optical element and subsequently used to generate frequency comb in nonlinear waveguide. Ultimately, at the conclusion of these steps, a frequency comb is generated with substantially flat optical spectrum, while retaining variability with respect to the frequency pitch, high coherency and substantially wide spectral band of coverage.

The invention relates to a high-sensitivity up-conversion single photon detection system. The system comprises an adjustable attenuator for receiving pumping laser emitted by a laser device; an output end of the adjustable attenuator is connected with an input end of a beam splitter; the output end of the beam splitter is respectively connected with a power meter and a wavelength-division multiplexer which is used for receiving signal light to be coupled; the output end of the wavelength-division multiplexer is connected with the input end of a nonlinear waveguide; and a single photon detector is arranged at the output end of the nonlinear waveguide. In the invention, the pumping laser enters into the nonlinear waveguide with the signal light by wavelength-division multiplexing, and the nonlinear waveguide can eliminate Raman noise to a great extent. In the nonlinear waveguide, the signal light can be converted up into visible light, and the up converted visible photons are collected in the single photo detector for detection.

A handpiece can treat biological tissue using electromagnetic radiation, which can be substantially fluorescent light. The handpiece includes a source of electromagnetic radiation and a nonlinear waveguide. The nonlinear waveguide is adjacent the source, receives electromagnetic radiation from the source, and delivers the electromagnetic radiation to the biological tissue. The handpiece also includes a system for circulating a fluorescent substance through the nonlinear waveguide. The fluorescent substance is capable of modulating at least one property of the electromagnetic radiation.

The invention discloses a nonlinear polarization rotation effect based all-optical adding and subtracting device. The all-optical adding and subtracting device comprises a set of input polarization controllers, a set of optical attenuators, a light-combining device, a nonlinear polarization rotation device, a light splitting device, a set of polarization controllers and a set of polarized beam splitters. The device adopts a principle as follows: after data light and non-modulated light are simultaneously injected into a nonlinear optical fiber or a nonlinear waveguide, an optical power change is introduced into a nonlinear relative phase shift, thereby resulting in the rotation of polarization states of optical signals. At the output end of the nonlinear optical fiber or waveguide, the orthogonal polarization states of multiple wavelength signals are simultaneously filtered by the light splitting device and the polarized beam splitters, so that various basic combinational logics are completed, and an all-optical half adder, a half-subtracter, a full adder and a full subtracter are realized. According to the invention, the logic operation of signals is directly completed in an optical domain, so that an electronic bottleneck is broken through, and a Tb/s-magnitude all-optical adding and subtracting operation can be realized, and therefore, the device disclosed by the invention can be applied to the fields of light-speed optical signal processing and light-speed optical switching networks and the like.

A monolithically integrated wavelength converted photonic integrated circuit (PIC) is fabricated by forming a trench in the PIC's insulating layer to expose a portion of an output waveguide that transmits a photonically processed optical signal at frequency ω1. A non-linear waveguide formed of a non-linear material with non-linear susceptibility at frequency ω1 and a transmission bandwidth spanning both ω1 and m*ω1 where m is an integer of at least two is fabricated in direct physical contact with the exposed portion of the output waveguide. A patterned structure is fabricated in or on the non-linear waveguide to enhance non-linear susceptibility to generate an optical signal at frequency m*ω1, which may be emitted directly or coupled to an optical antenna.

The invention discloses a method utilizing metal gratings to achieve wideband adjustable silicon waveguide optical non-linear four wave fixing enhancement. A silicon waveguide is arranged on a metal underlay, which is characterized in that metal gratings are periodically arranged on the silicon waveguide. According to the invention, the enhancing wideband and enhancing factors of the silicon waveguide optical non-linear four wave mixing are determined by the silicon waveguide and the geometric parameters and the grating period of the metal gratings. The invention has the advantages of simply structure and easiness in implement; via properly selecting parameters, a wideband adjustable silicon waveguide optical non-linear four wave fixing enhancement effect is obtained, thus the reliability of the development of the non-linear optical elements is guaranteed, e.g. an optical switch, a logical gate, a memory, an adjustable non-linear waveguide and the like, which are recently disclosed in an all optical communication network.

With a wavelength conversion device based on a nonlinear optical effect, when arrayed waveguides including an intended nonlinear waveguide are fabricated, unwanted slab waveguides are inevitably formed. The slab waveguides can cause an erroneous measurement in the selection of a waveguide having desired characteristics from the arrayed waveguides. The erroneous measurement can lead to redoing steps for fabricating the wavelength conversion device and a decrease in the yield and inhibit the evaluation of the characteristics in selection of the waveguide and the subsequent fabrication of the wavelength conversion device from being efficiently performed. A wavelength conversion device according to the present invention includes a plurality of waveguides formed on a substrate, and a plurality of slab waveguides that are arranged substantially in parallel with and spaced apart from the plurality of waveguides, and each of the slab waveguides has a grating structure that reflects light of a particular wavelength.

A non-linear waveguide comprises a transmission line including a first conductive line and a second conductive line; a first bias voltage supply connected with the transmission line; and one or more pairs of diodes connected between the first conductive line and the second conductive line, the one or more pairs of diodes including: a first diode having an anode connected with the first conductive line and a cathode connected with the second conductive line; a second diode having a cathode connected with the first conductive line and an anode connected with the second conductive line; and a second bias voltage supply connected between the anode of the second diode and the second conductive line.

A tunable parametric mixer comprising a pump laser, a nonlinear waveguide, and a refractive index tuner. The pump laser is configured to generate pump photons. The nonlinear waveguide comprises a cladding and a core. The core is made of nonlinear optical material and the cladding in made of a material with a tunable index of refraction. The nonlinear waveguide is configured to convert the pump photons into signal and idler photons. The refractive index tuner is configured to change the refractive index of the cladding to dynamically tune the dispersion properties of the nonlinear waveguide in order to alter a spectral location of a gain band of the parametric mixer.

The invention relates to a hybrid integrated optical communication waveband on-chip quantum entanglement source, which comprises a laser generation and amplification module and a nonlinear optical module, the nonlinear optical module is formed by connecting two sections of nonlinear waveguides through a second harmonic filter; under the action of optical communication waveband pump light, second harmonic generation and spontaneous parametric down-conversion processes successively occur in the two sections of nonlinear waveguides, so that quantum entanglement two-photon generation is realized. The second harmonic filter connected with the two waveguides can effectively restrain residual pump light, and noise is prevented from being introduced into entangled two photons in the spontaneous Raman scattering process. All devices required by the on-chip quantum entanglement source are integrated on the same substrate material, so that the volume of the quantum entanglement source is effectively reduced. The hybrid integrated optical communication waveband on-chip quantum entanglement source provided by the invention has the characteristics of high integration level, high brightness and low noise, can be realized through an advanced micro-nano processing and packaging technology, and is beneficial to the integration and practical development of quantum light sources.

The invention discloses a soliton all-optical diode based on a waveguide array and a realization method thereof. The soliton all-optical diode comprises an encapsulation shell, an artificial gauge field arranged in the encapsulation shell and used for regulating an optical path, and the nonlinear waveguide array embedded in the artificial gauge field and used for inducing solitons; the artificialgauge field comprises a magnetic field and other effect fields with a magnetic field effect. The realization method includes the steps that the waveguide array is embedded in the artificial gauge field, and the artificial gauge field is adopted for adding a phase related to the direction of the optical path to signal light entering the waveguide array to realize unidirectional transmission of theoptical path; the nonlinearity and periodicity of the waveguide array are utilized for inducing the unidirectionally transmitted signal light entering the waveguide array to become discrete solitons,and the optical field shape of the signal light being unidirectionally transmitted in the waveguide array is kept unchanged. The all-optical diode with high fidelity, high degree of freedom and high tunability is provided, high-quality optical information processing and optical communication are realized, and the all-optical diode is suitable for optical communication products and optical information processors which require high optical signal quality.

A microscopy system, including: a mode-locked fiber laser (110) configured to output a pulse having a center wavelength; a nonlinear waveguide (120) configured to shift the wavelength of the pulse from the mode-locked fiber laser; a fiber amplifier (130) configured to amplify the output from the first nonlinear waveguide; a second-harmonic generator (140) configured to generate femtosecond pulses at twice the optical frequency from the output of the fiber amplifier; and an imaging system (150).

With a wavelength conversion device based on a nonlinear optical effect, when arrayed waveguides including an intended nonlinear waveguide are fabricated, unwanted slab waveguides are inevitably formed. The slab waveguides can cause an erroneous measurement in the selection of a waveguide having desired characteristics from the arrayed waveguides. The erroneous measurement can lead to redoing steps for fabricating the wavelength conversion device and a decrease in the yield and inhibit the evaluation of the characteristics in selection of the waveguide and the subsequent fabrication of the wavelength conversion device from being efficiently performed. A wavelength conversion device according to the present invention includes a plurality of waveguides formed on a substrate, and a plurality of slab waveguides that are arranged substantially in parallel with and spaced apart from the plurality of waveguides, and a guided light attenuator is formed in each of the slab waveguides. The guided light attenuators allow efficient selection of a waveguide having desired optical characteristics from the plurality of waveguides. The light attenuation by the guided light attenuators can be changed in steps for fabricating the wavelength conversion device.

An all-optical PPM modulator comprises one or more sources of trains of optical control pulses and optical signal pulses, the optical control and optical signal pulses being equally spaced, but differentiated from one another by at least having different optical wavelengths and/or polarizations prior to modulation. An electro-optic modulator, for example, amplitude modulates the control pulses using a signal. A chirped Bragg reflector in an non-linear waveguide receives both the amplitude modulated optical control signal pulses and unmodulated optical signal pulses at an entrance port thereof, the waveguide having a path length selected to achieve temporal overlap of the control and signal pulses in the waveguide. The chirped Bragg reflector is resonant to the optical signal pulses and off-resonant to the optical control pulse. The signal pulses reflect the in chirped Bragg reflector and exit an entrance port thereof while the control pulses either are absorbed or exit an exit port of the chirped Bragg reflector.

The invention discloses a coherent laser radar and a water flow velocity detection method. The invention provides a water flow velocity coherent detection technical scheme based on frequency down-conversion. The method comprises the following steps: detecting water flow and turbulence of each water layer by adopting visible light band laser with penetrating power to the water flow to obtain an echo signal; mixing the local oscillator signal and the echo signal with the pump laser, and performing frequency down-conversion by using a nonlinear waveguide to obtain a near-infrared band or infraredband to-be-detected signal which is easy for coherent detection so as to perform coherent beat frequency. The technical scheme disclosed by the invention can be used for finely detecting the water flow velocity of each water layer and the turbulent flow velocity in the vertical direction, so that the integration level of the system can be improved, and the system can be conveniently carried on various platforms.

The invention discloses an implementation method and an implementation device for a full-adder and a full-subtractor. According to the method, three input optical signals are processed by utilizing third-order nonlinear effects in nonlinear waveguides to obtain the output of the full-adder and the full-subtractor. The device comprises first to sixth light wavelength division multiplexers, first to third nonlinear waveguides, first to third polarization controllers, a polarization analyzer, a first light wavelength division multiplexer and a second light wavelength division multiplexer. Compared with other devices for implementing an all-optical full-adder and an all-optical full-subtractor, the device processes three paths of input optical signals by utilizing three nonlinear waveguides to realize the logic operation of full-addition and full-subtraction. Ultra-quick response nonlinear effects are adopted, and the method and the device are applied to the processing and computation of high-speed optical signals. The method and the device are easy to implement, and can work under a high-speed condition. Logic information carried by two wavelengths is converted into a wavelength conversion process of a single wavelength, so that the quality of the signals can be recovered, the extinction ratio of output signals of the full-adder and the full-subtractor can be increased, and the application of the full-adder and the full-subtractor to an optical communication system is facilitated.

A non-linear waveguide cone for manufacturing fault tolerance of waveguide transitions may be designed by: for each of a plurality of sets of parameter values characterizing the waveguide transitions (e.g., a set of nominal parameter values and a set of parameter values associated with a process corner representing a process variation from the nominal parameter values); calculating the scattering rate associated with the waveguide transition as a function of the waveguide width of the waveguide cone; determining an envelope of the calculated width dependent scatter; and calculating a non-linear cone profile of the waveguide cone based on the envelope. For the plurality of sets of parameter values, light propagation and coupling along the waveguide transition may be further computationally simulated to determine a minimum transmission value associated with the waveguide transition for a specified cone length, and/or to determine a minimum cone length at which the transmission value associated with the waveguide transition exceeds a specified threshold transmission value.

The invention provides a single-input multi-output optical switch based on non-linear photon crystal lattices. The single-input multi-output optical switch based on non-linear photon crystal latticesincludes a first waveguide layer, a second waveguide layer and a third waveguide layer, wherein the first waveguide layer is arranged at the upper portion of the second waveguide layer, and the secondwaveguide layer is arranged between the third waveguide layer and the first waveguide layer; the second waveguide layer comprises a nonlinear waveguide, and each of the first waveguide layer and thethird waveguide layer comprises a linear waveguide; the nonlinear waveguide is a sinusoidal waveguide, and each linear waveguide is a spiral waveguide; and the optical switch also includes an input port and at least two output ports. The single-input multi-output optical switch based on non-linear photon crystal lattices can select different output ports according to actual needs, and the opening/closing threshold of the optical switch of corresponding to each output port is different, thus increasing the flexibility in practical applications.