52 results about "Optical circulators" patented technology

An optical fiber loop has a gain medium having a gain at an oscillation wavelength and optical circulators 13 and 14. Collimate lenses 22 and 24 enlarge light bean taken from the optical circulators 13 and 14. A polygon mirror 25 is provided on the light axis, and is rotated. A diffraction grating 27 is provided at the receiving position of the light reflected by the polygon mirror 25, and is of a Littrow configuration which reflects the light in the same direction as the incident light. A selected wavelength changes according to an incident angle to the diffraction grating 27, resulting in increase of selectivity owing to twice incident, thereby permitting to change an oscillation wavelength with narrow band even when changing the selected wavelength by rotating the polygon mirror 25 at high speed.

A magnetic garnet single crystal film formation substrate 2 for growing a thick magnetic garnet single crystal film, wherein crystal defects, warps, cracks and flaking, etc. are not caused, by liquid phase epitaxial growth is provided. The substrate 2 comprises a base substrate 10 composed of a garnet-based single crystal being unstable with a flux used for the liquid phase epitaxial growth; a buffer layer 11a composed of a garnet-based single crystal thin film formed on a crystal growing surface 10a of said base substrate 10 and being stable with said flux; and a protective layer 11b formed at least on side surfaces 10b of said base substrate 10 crossing with said crystal growing surface of said base substrate 10 and being stable with said flux. By using the substrate, a high quality magnetic garnet single crystal film can be produced. The magnetic garnet single crystal film is used as an optical element, such as a Faraday element, used for an optical isolator, optical circulator and magneto-optical sensor, etc.

An axially symmetric permanent magnet structure with tunable longitudinal fields is described wherein selected radial magnet sectors in a truncated Halbach array configuration are tiltable. The tunable magnet structure is particularly useful in Faraday devices, such as Faraday rotators, Faraday mirrors, optical circulators and optical isolators.

There have been problems that a capturing device requires an optical source having a large power output, and a scanning operation and a capturing operation must be alternately performed by the respective devices.

A capturing device is provided with an optical receiver which receives a beam from outside as a reception beam, a reception beam capturing unit which performs a capturing operation by which the reception beam is introduced to the optical receiver, an optical transmitter which generates a transmission beam transmitted to the outside, a transmission beam scanning unit which performs a scanning operation of the transmission beams, and an optical circulator wherein the incidence of the reception beam and the exit of the transmission beam are performed at the same terminal.

The invention discloses a defective magneto photon crystal with a non-reciprocity feature and a purpose. The defective magneto photon crystal with the non-reciprocity feature comprises a one-dimensional magneto photon crystal and a magneto-optic material defect layer, the one-dimensional photon crystal is composed of magneto-optic material A and isotropic medium material B in an alternation mode, and the magneto-optic material C located at the middle of the structure is a magneto-optic material defect layer. The structure of the defective magneto photon crystal with the non-reciprocity feature is [A/B]m[C][A/B]mA, wherein the dielectric tensor of the magneto-optic medium is epsilon a, FORMULAE (as shown in the description), the thickness da is equal to 69.3 nanometers, the dielectric constant of the medium layer B is epsilon b=4, db is equal to 152.8 nanometers, the lattice period is d=da+db=222.1 nanometers, the dielectric tensor of the defect layer C is epsilon c, FORMULAE (as shown in the description), wherein m is the periodicity of the photon crystal, and m is equal to 13. The defective magneto photon crystal with the non-reciprocity feature is featured with simple structure, easiness in technique, strong functionality and the like, the design is flexible, and the application prospect is broad in opto-isolators, optical circulators and the like aspects.

The invention discloses a self-locking photoelectric oscillator and a method thereof. The self-locking photoelectric oscillator includes devices such as a semiconductor optical amplifier, an optical circulator, a narrow-band optical filter, a fiber beam splitter, a comb optical filter, an electrooptical modulator, a photoelectric detector, a microwave amplifier, and a microwave coupler and the like. A closed optical loop formed by the semiconductor optical amplifier, the optical circulator, the narrow-band optical filter, an output end of the fiber beam splitter and the comb optical filter generates stable single longitudinal mode laser output. A closed photoelectric loop formed by the other output end of the fiber beam splitter, the electrooptical modulator, the optical circulator, the comb optical filter, the photoelectric detector, the microwave amplifier and an output end of the microwave coupler generates stable single-frequency microwave signals. Multi-order harmonic-wave sidebands generated through modulation of the photoelectric loops undergo model selection via the comb optical filter so that a frequency self-locking effect is generated and generated microwave signals have the advantages of great frequency stability and high frequency purity.

A fiber-optic transmitter comprises a transmitter optical port, an optical circulator, a semiconductor optical amplifier, and a two-port modulation-averaging structure. The optical circulator has at least three ports, a first one of the three circulator ports being optically coupled to the transmitter optical port. The semiconductor optical amplifier has an input optical port, an output optical port, and an electrical input port. The two-port modulation-averaging structure is optically coupled between the input optical port and a third one of the three circulator ports.

A loop is formed with an optical fiber by providing a gain medium having a gain with respect to an oscillation wavelength. Light retrieved by the optical circulator 13 from the optical fiber loop is enlarged and projected to a mirror 23. A diffraction grating 25 is provided with respect to the light reflected in the mirror. The diffraction grating 25 has a Littrow arrangemnt wherein the light is reflected in a same direction as incident light. A selected wavelength is changed in accordance with an incident angle with respect to the diffraction grating 25. Therefore, when the mirror 23 is rotated so as to change the selected wavelength, the oscillation wavelength can be changed at high speed.

A miniaturized optical circulator includes: two polarized beam splitters and a 45-degree Faraday rotator (300). An optical signal of a first optical path is input from a common terminal (T1) and then is separated into a first polarization component and a second polarization component by a first polarized beam splitter (100), the first polarization component first passes through the 45-degree Faraday rotator (300), reached a second polarized beam splitter (400) and then is reflected back, and at least successively passes through the 45-degree Faraday rotator (300) and the first polarization beam (100), and reached a receiving terminal (T2); the second polarization component at least under goes one reflection of the first polarized beam splitter (100) subsequent to being separated, and reaches the receiving terminal (T2); the optical signal of a second optical path is input from a transmitting terminal (T3), successively passes through the second polarized beam splitter (400), the 45-degree Faraday rotator (300), and the polarized beam splitter (100), and is output by the common terminal (T1). The optical circulator is small in volume and low in costs, and is easy to integrate.

The invention discloses an optical circulator and a single-fiber bidirectional optical module using the same. The optical circulator comprises a transmitting end, a receiving end, a common end, a first polarization beam splitter, a second polarization beam splitter, a half wave plate and a faraday rotator. When the transmitting end transmits parallel direction polarized beams, the parallel direction polarized beams arrive at the common end at least passing the first polarization beam splitter, the half wave plate, the faraday rotator and the second polarization beam splitter in sequence; when the common end sends an optical signal, the optical signal is decomposed into a first polarized component and a second polarized component through the second polarization beam splitter, the polarization direction of the first polarized component is perpendicular to the polarization direction of the second polarized component, the first polarized component arrives at the receiving end at least passing the faraday rotator, the half wave plate and the first polarization beam splitter in sequence, and the second polarized component arrives at the receiving end at least passing the second polarization beam splitter, the faraday rotator, the half wave plate and the first polarization beam splitter in sequence. Only two polarization beam splitters are used, cost is low, and the size is small.

The invention relates to a method for expanding a quantum secret communication network and a novel full-time all-pass quantum network router. The invention is characterized in that the expandability of a quantum secret communication network is enhanced and the consumption of optical wavelength resources is reduced by combining the characteristics of quantum key distribution and introducing an optical circulator and a polarizing beam splitter to increase the degrees of freedom of optical signals. For a quantum secret communication network having N numbered optical wavelength resources, a maximum of 4N+1 numbered network users can be supported. Each port of the quantum network router is provided with an external interface and a plurality of internal interfaces, wherein the external interface and the internal interfaces are respectively used for the connection with quantum secret communication network users and the connection among internal ports. By using the quantum network router as the core, a full-time all-pass backbone quantum secret communication network can be effectively constructed.

Provided is an optical circuit element and, particularly, an optical circulator or the like, that exhibits an excellent extinction ratio and that can be easily produced at a decreased cost. An optical circuit element comprising, in combination, two polarized light-separating elements, two totally reflecting mirrors, at least a piece of polarizing plane rotating element independent of a direction of travel of light, at least a piece of polarizing plane rotating element dependent of a direction of travel of light, a plurality of light incident/outgoing ports, and a magnetic field application means, wherein said polarized light-separating elements and said totally reflecting mirrors are formed of the same or different multi-layer polymer films.

The invention provides a tunable Brillouin Raman multi-wavelength fiber laser, belongs to the technical field of fiber laser, and aims at solving the problems existing in the present multi-wavelength laser. A tunable Brillouin pump light source is connected with the first port a of an optical coupler. The second port b of the optical coupler is connected with the third port e3 of a first optical circulator. The third port c of the optical coupler is connected with the first port e1 of the first optical circulator. The fourth port d of the optical coupler is connected with a spectrum analyzer. The second port e2 of the first optical circulator is connected with the first port f of a wavelength division multiplexer. The second port g of the wavelength division multiplexer is connected with a Raman pump source. The common port h of the wavelength division multiplexer is connected with one port of a dispersion compensation fiber. The other port of the dispersion compensation fiber is connected with the second port i2 of a second optical circulator. The first port i1 of the second optical circulator is connected with the third port i3 of the second optical circulator to form a loop. The tunable Brillouin Raman multi-wavelength fiber laser is suitable for the field of optical communication, optical sensing and microwave photonics.

The invention discloses a three-port optical circulator. The three-port optical circulator comprises a double-optical-fiber collimator, a first beam splitting/combining crystal, a first-group polarization state converter, a light beam loop circuit device, a second-group polarization state converter, a second beam splitting/combining crystal and a single-optical-fiber collimator which are sequentially arranged on the longitudinal axis of the optical circulator. The light beam loop circuit device is formed by machining three wedge angle faces on a single birefringent crystal and serves as a crystal polarization beam splitting prism formed by three light-transmitting end faces, the optical axis of the crystal polarization beam splitting prism is located in an incident plane and forms an included angle with the longitudinal axis, and azimuth angles alpha1, alpha2 and alpha3 of the light-transmitting end faces and an azimuth angle theta of the optical axis are matched with light beam staggered-coupled angles beta of the double-optical-fiber collimator. Due to the fact that the single crystal prism is adopted as the light beam loop circuit device, a light loop device formed by combining multiple conventional optical elements is omitted, the size is decreased, assembly is facilitated, the product performance is effectively improved, and meanwhile the cost is also reduced.

The invention provides an asymmetric directional coupler which comprises a substrate, top silicon is arranged on the substrate and comprises a first port, a coupling area, a first output waveguide and a second output waveguide, one end of the coupling area is connected with the first port, and the other end of the coupling area is connected with the first output waveguide and the second output waveguide. The coupling area is covered with a phase change material layer, the coupling area is divided into N * M rectangular units, a non-periodic first punching array meeting a preset first output target is formed by adjusting the state of the rectangular units, and the first output target refers to the sum of the transmittance of the first output waveguide and the transmittance of the second output waveguide; the asymmetric directional coupler provided by the invention is small in size, easy to process, stable in performance and capable of realizing regulation and control of a light propagation path.

The invention provides an optoelectronic oscillator based on a germanium modulator, and relates to the field of radio frequency components. The optoelectronic oscillator comprises an input spot-size converter, the germanium modulator and an output spot-size converter. The input spot-size converter, the germanium modulator and the output spot-size converter are integrated on the same chip which is arranged on an SOI wafer. The optoelectronic oscillator further comprises a light source. The light source is coupled to the germanium modulator through the input spot-size converter. The output spot-size converter is connected with the end B of an optical circulator. The end C of the optical circulator is connected with an optical fiber delay line, an erbium-doped fiber amplifier and the end A of an optical coupler in sequence. The end B of the optical coupler is connected with the end A of the optical circulator. The germanium modulator is connected with an electric band-pass filter which is connected with the end B of an electric circulator, the end C of the electric circulator is sequentially connected with an electric amplifier and the end A of an electric coupler, and the end B of the electric coupler is connected with the end A of the electric circulator. According to the optoelectronic oscillator based on the germanium modulator, active devices are highly integrated, the occupied space is small, the power consumption is low, and the cost of the optoelectronic oscillator is reduced.

The invention relates to the field of optics, and provides a three-port optical circulator. The three-port optical circulator comprises a dual-fiber collimator, a ridge prism, a first light splitting crystal, a first half-wave plate assembly, a second light splitting crystal, a second half-wave plate assembly, an optical rotation crystal, a third light splitting crystal and a single-fiber collimator, which are all disposed in sequence in an optical path direction. A magnet ring sleeves the periphery of the optical rotation crystal. The first half-wave plate assembly comprises a first half-wave plate and a second half-wave plate, which are disposed in the first quadrant and in the third quadrant, perpendicular to the optical path direction, of a two-dimensional rectangular coordinate system respectively. The optical axis of the first half-wave plate and the optical axis of the second half-wave plate are parallel to each other, and each optical axis is at an angle of 45 degrees to a horizontal plane. The second half-wave plate assembly comprises a third half-wave plate and a fourth half-wave plate, which are arranged side by side on a plane perpendicular to the optical path direction. Compared with a conventional three-port optical circulator, the three-port optical circulator of the invention has the advantages that only one optical rotation crystal is adopted, people do not need to arrange multiple stacked magnetic fields for an optical rotation crystal occasion that can only adopt a nonsaturated magnetic field, and the circulator is compactor in structure, small in size and low in cost.

The invention discloses an optical circulator based on a non-spacing directional coupling structure. The invention is formed by orderly and serially connecting an input Y-branch waveguide, a rectangular dual-mode waveguide provided with magnetic material, and an output Y-branch waveguide on a substrate. The proposal of the invention is to adopt the non-spacing directional coupling structure and utilize the non-reciprocal phase shift difference principle of a basic mode and a one-off pattern thereof to realize the integration of an optical isolator and the optical circulator through the non-reciprocal phase shift. The non-reciprocal device has the characteristics of compact structure and high integration level, has application prospect in aspects such as emission, amplification, transmission, and routing of light signals and so on, and has scientific research significance and application value.