65 results about "Faraday rotator" patented technology

The invention relates to the technical field of laser ranging, in particular to a double-optical-comb hybrid ranging device which comprises a signal detection optical path system and a signal demodulation optical path system. Wherein the signal detection optical path system comprises a first optical frequency comb, a first optical isolator, a first optical collimator, a first beam splitter prism, a reference mirror, a Faraday rotator, a convergence mirror and a target reflector; the signal demodulation optical path system comprises a second optical frequency comb, a second optical isolator, a second optical collimator, a half-wave plate, a second beam splitter prism, a third beam splitter prism, a first polarization controller, a first photoelectric detector, a reflector, a polarization beam splitter prism, a second polarization controller and a second photoelectric detector. A third polarization controller; and a third photoelectric detector. According to the invention, three ranging technologies of asynchronous optical sampling ranging, multi-heterodyne interference ranging and synthetic wavelength ranging are fused, and the problem that a large ranging range and high ranging precision cannot be simultaneously considered in the ranging process is solved.

The utility model is suitable for the technical field of optical fiber sensing, and relates to a double-interferometer push-pull and common-mode noise differential suppression optical fiber hydrophone, which comprises a first thin-wall cylinder, a second thin-wall cylinder, a first optical fiber interferometer and a second optical fiber interferometer, the first thin-wall cylinder is embedded in the second thin-wall cylinder, a first optical fiber winding area and a second optical fiber winding area are arranged on the first thin-wall cylinder, and a third optical fiber winding area and a fourth optical fiber winding area are arranged on the second thin-wall cylinder; the first optical fiber interferometer comprises a first short-arm sensing optical fiber, a first long-arm sensing optical fiber, a first Faraday rotating mirror and a second Faraday rotating mirror, and the second optical fiber interferometer comprises a second short-arm sensing optical fiber, a second long-arm sensing optical fiber, a third Faraday rotating mirror and a fourth Faraday rotating mirror. According to the utility model, the dual-push-pull structure is formed by the dual-fiber interferometer, so that temperature drift noise and optical scattering noise caused by the ultra-long sensing fiber are reduced, and common-mode noise formed by light source vibration, transmission optical cable jitter and the like is suppressed.

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

This invention discloses a 9-cavity mode-locked fiber laser with adjustable parameters based on a liquid crystal phase delay device, belonging to the field of mode-locked laser technology. It includes, along the optical path, a mirror, a polarizing beam splitter prism, a liquid crystal phase delay adjustable waveplate, a Faraday rotator, a liquid crystal phase delay adjustable waveplate, and a polarizing beam splitter prism. A fiber optic loop is provided on one side of the polarizing beam splitter prism, comprising, in sequence, a fiber collimator, a gain fiber, a wavelength division multiplexing-splitter mixer, and a fiber collimator prism. The slow axis of the fiber collimator prism's pigtail is aligned horizontally with the polarizing beam splitter prism prism 2; the slow axis of the fiber collimator prism 2's pigtail is aligned vertically with the polarizing beam splitter prism prism 2. A pump semiconductor laser is connected to the pump input of the wavelength division multiplexing-splitter mixer, and an FCAPC jumper is connected to the signal output of the wavelength division multiplexing-splitter mixer. This enables continuous and rapid adjustment of the laser parameters.

This invention provides an optical isolator (81) with two or more optical paths, characterized in that each optical path comprises an isolator chip (3) formed by interconnecting one or more polarizers (4) and one or more Faraday rotators (5). The isolator chip (3) and a substrate are bonded and fixed together. The substrate is a light-transmitting substrate (2), and light passing through the optical path is transmitted through the isolator chip (3) and the light-transmitting substrate (2). Thus, for optical isolators inserted into laser modules with multiple optical paths, an optical isolator is provided that does not require the isolator chip to be placed in space outside the light-transmitting part, and simplifies the assembly process of the isolator chip.

The present invention provides defect-controlled fluoride crystals, a method for producing the same, and the use thereof. These fluoride crystals contain at least a rare earth element RE (RE is at least one element selected from the group consisting of cerium (Ce), praseodymium (Pr), lanthanum (La), and neodymium (Nd)), fluorine (F), and hydrogen (H), and have the same crystal structure as crystals represented by CeF3. A method for producing fluoride crystals according to the present invention comprises growing crystals from a raw material containing a rare earth element RE and a raw material containing fluorine (F) by a solvothermal method in the presence of at least one mineralizer selected from the group consisting of mineralizers containing an alkali metal element and / or an alkaline earth metal element, acid mineralizers, and mineralizers containing a normal salt.

Embodiments herein relate to systems, apparatuses, or processes directed to an integrated optical coupler that may be used to optically couple a waveguide and a PIC. In embodiments, the integrated optical coupler may include an optical diffraction grating mechanism, an optical lens, and a Faraday rotator. In embodiments, the integrated optical coupler may at least partially within a housing. Other embodiments may be described and / or claimed.

The application discloses a machine learning assisted fiber-optic gyroscope polarization locking and slow drift compensation system. The system can intelligently search and predict the relationship between the fiber-optic gyroscope interference error signal and the incident light polarization direction by introducing the neural network in machine learning, and feed back the predicted optimal value to the hardware system for compensation, thereby realizing the functions of fiber polarization locking and suppressing the intensity slow drift of the output signal. The system comprises a coherent light source, a Glan laser prism, a first polarization beam splitter, a first mirror, a first Faraday rotator, a first half-wave plate, a liquid crystal modulator, a polarization maintaining optical fiber, a phase modulator, a second Faraday rotator, a second half-wave plate, a second mirror, a third half-wave plate, a second polarization beam splitter, a photodetector, a computer and a signal generator. The application also discloses a machine learning assisted fiber-optic gyroscope polarization locking and slow drift compensation method realized by using the above system.

The present invention provides a bismuth-substituted rare earth iron garnet single crystal which suppresses valence variation of Fe ions and is suitable for a Faraday rotor and an optical isolator having reduced insertion loss. The bismuth-substituted rare earth iron garnet single crystal according to the present invention is characterized by a composition formula of (Tb a Ln b Bi c Mg 3‑(a+b+c) )(Fe d Ga e Ti f Pt 5‑(d+e+f) )O 12 In the composition formula, 0.02 ≤ f ≤ 0.05, 0.02 ≤ {3-(a+b+c)} ≤ 0.08, and -0.01 ≤ {3-(a+b+c)}-{f+5-(d+e+f)} ≤ 0.01. Furthermore, Ln is a rare earth element and can be selected from Eu, Gd, Ho, Tm, Yb, Lu, and Y.

The invention relates to a method for growing a terbium lithium fluoride magneto-optical crystal by using a fluxing agent. The process comprises the following steps: (1) fully mixing a fluxing agent with raw materials; (2) putting the mixture into a crucible, feeding the crucible into a high-temperature molten salt furnace, vacuumizing the furnace, and introducing protective gas; and (3) controlling the heating rate, heating until the mixture is completely molten, and keeping the temperature for several hours. And (4) slowly cooling until crystals are completely separated out. And (5) annealing to room temperature to obtain the terbium lithium fluoride crystal. Tests show that the terbium lithium fluoride crystal prepared by the method is good in quality, large in extinction ratio and high in damage threshold, has relatively high transmittance and relatively strong magneto-optical performance in wave bands of 505nm, 633nm, 880nm and 1064nm, and is expected to be practically applied to magneto-optical devices such as magneto-optical isolators, Faraday rotators and the like.

An optical isolator includes a polarizer for receiving an optical signal from an optical signal source, a Faraday rotator for rotating a polarization of the optical signal output by the polarizer and outputting the same as a rotator output optical signal, and an analyzer for receiving the rotator output optical signal and for outputting at least a part thereof. The polarizer and the analyzer each include a number of spaced elongated dielectric ridges coupled to the Faraday rotator. Each dielectric ridge has a length direction extending along one surface of the Faraday rotator and pair of spaced sides extending away from the one surface of the Faraday rotator. Each dielectric ridge includes an electrically conductive coating on each side of the dielectric ridge.

The application discloses a kind of based on non-interacting polarization multiplexing multi-path pulse compression device and method, it is related to ultrafast laser technology and nonlinear optics field, device includes: first polarization beam splitter, Faraday rotator, second polarization beam splitter and dispersion compensation module, dispersion compensation module is used to make pulse multiple pass through same dispersion compensation element and form return pulse, return pulse is converted into polarization state orthogonal with incident state by Faraday rotator after by first polarization beam splitter output. By Faraday non-interacting coaxial architecture, pulse keeps high-efficiency polarization matching, reduces astigmatism, spatial chirp and energy loss caused by off-axis folding, and when target dispersion amount is certain, optical envelope volume is reduced, and element light aperture requirement is reduced;While pulse compression and reverse light isolation are integrated in the same magneto-optical component, reduce the number of discrete components, improve system compactness and stability.

We provide a light circulator that allows for easy detection of damage. [Solution] The device includes a first port P1 into which light is incident, a second port P2 from which light incident from the first port P1 is emitted, a third port P3 from which light incident from the second port P2 is emitted, a first polarizer 5 and a second polarizer 6 located on the first port P1 side, a third polarizer 7 located on the second port P2 side and positioned together with the first polarizer 5 to sandwich the second polarizer 6, a Faraday rotator 8 located between the first polarizer 5 and the second polarizer 6, and a half-wave plate 9 located between the second polarizer 6 and the third polarizer 7, and includes a light emission unit 3 into which a portion of the light incident from the first port P1, passing through the first polarizer 5, the Faraday rotator 8, the second polarizer 6 and the half-wave plate 9, and incident on the third polarizer 7 is reflected and emitted as reflected light.

Described herein are systems and methods for enabling small high-magnification cameras or imaging systems to operate in low-light (e.g. night time) conditions. These systems include the use of reflective polarizers and non-reciprocal elements (Faraday rotators) to enable a longer light path, and to enable light from an image to reach the sensor.

Method for laser material processing using a processing laser beam (3), wherein a first laser beam (8a), which is coupled into at least a first fiber core (9a) of an optical multicore fiber (9), and a second laser beam (8b), which is coupled into at least a second fiber core (9b) of the multicore fiber (9), are generated from a polarized input laser beam (5) using a birefringent crystal (7), wherein by influencing the polarization of the input laser beam (5) the ratio in which the power of the input laser beam (5) is divided between the first and the second laser beam (8a, 8b) is changed with a modulation frequency (f) between 1 Hz and 100 kHz, in particular between 100 Hz and 100 kHz, and thereby the first and the second laser beam (8a, 8b) can be coupled out of the multi-core fiber (9) alone or together as a processing laser beam (3). characterized by that the polarization is influenced by switching between linearly, circularly or elliptically polarized polarization by means of an electro-optic polarization modulator (6), in particular a Pockels cell or Faraday rotator, which can be controlled with the modulation frequency (f) to change the polarization of the input laser beam (5).

This utility model relates to a low-cost integrated module for a polarization-independent optical circulator and filter, comprising a first collimator, a circulator core, and a second collimator arranged sequentially. The first collimator is a four-fiber collimator, and the second collimator is a single-fiber collimator. The circulator core consists of a first polarizing beam splitter, a half-wave plate, a Faraday rotator crystal, a second polarizing beam splitter, a first filter, a first reflector, a second filter, a second reflector, and a magnetic block. The angle between the first filter and the first reflector is α; the angle between the second filter and the second reflector is also α. This design effectively realizes the circulator and wavelength division multiplexing functions during optical signal transmission. This design not only avoids unnecessary signal reflection and loss but also enhances the isolation of the optical circulator, achieving double-stage isolation. Wavelength division multiplexing can be achieved through small-angle incident light, making the optical path layout of the device more compact.

The invention discloses a bipolar isolator, and relates to the technical field of optical isolation, the bipolar isolator comprises a shaft shell and a sleeve shell, Faraday polarizers are arranged in the shaft shell and the sleeve shell, the end part of the shaft shell is provided with an insertion part, the end part of the sleeve shell is provided with an insertion cylinder matched with the insertion part, and the insertion part is in insertion fit with the insertion cylinder. Polarization beam splitters are arranged at one end, far away from the sleeve shell, of the shaft shell, one end, far away from the shaft shell, of the sleeve shell and in the insertion part; the polarization beam splitters are located on the axis of the Faraday rotator; the two spaces capable of containing the Faraday polarizers are provided through the two shaft shells and the two sleeve shells which are mutually matched and connected in an inserted mode, the two isolator bodies are formed in cooperation with the polarization beam splitters on the two sides and in the middle at the same time, bipolar isolation of light is achieved, the isolation degree is effectively improved, and meanwhile the matching structure of the shaft shells and the sleeve shells is simple, convenient to install and low in cost. The cost is saved.

We provide an optical circulator that can easily detect damage to the polarizer. [Solution] The device comprises a first port P1 into which light is incident, a second port P2 from which light incident from the first port P1 is emitted, a third port P3 positioned so as not to be located on a straight line connecting the first port P1 and the second port P2, from which light incident from the second port P2 is emitted, a first polarizer 5 positioned on the first port P1 side, a second polarizer 6, a third polarizer 7 positioned on the second port P2 side and positioned together with the first polarizer 5 to sandwich the second polarizer 6, and a Faraday rotator 8 positioned between the second polarizer 6 and the third polarizer 7, and a light emission section 3 in which the first polarizer 5 and the second polarizer 6 are positioned, and a portion of the light incident from the first port P1, passing through the first polarizer 5 and incident on the second polarizer 6 is reflected and emitted as reflected light.

The utility model relates to an intracavity frequency doubling laser, which comprises a pumping source, a light beam combiner and a bidirectional optical amplifier, and is characterized in that a first optical fiber collimator, a first Wollaston prism, a first roof prism, a first Faraday rotator, a polarizer, a frequency doubling crystal, a first reflection cavity mirror and a second reflection cavity mirror are sequentially arranged on one side of the bidirectional optical amplifier along an optical path; and a second optical fiber collimator, a second Wollaston prism, a second roof prism, a second Faraday rotator and a rectangular prism are sequentially arranged on the other side of the bidirectional optical amplifier along the optical path. According to the utility model, the two Faraday rotators and the polarizer are utilized, the oscillation of the linear polarization fundamental frequency laser is realized by using the non-polarization-maintaining gain fiber, the generation of the frequency doubling laser is realized through the frequency doubling crystal in the cavity, and finally the stable frequency doubling laser is output through the endoscope; the utility model has the characteristics of low manufacturing cost, high extinction ratio and high frequency doubling efficiency.

Disclosed are integrated photonics systems including integrated polarizing devices for implementing on-chip optical isolators and circulators. Implemented around a Faraday rotator isolator arrangement, integrated photonic components are arranged in a device to polarize and rotate the polarization of optical signals traversing forwards and backwards through the device to effect optical isolators and circulators.

This invention discloses a narrow-linewidth fiber laser system based on a self-injection locked feedback mechanism, belonging to the field of fiber optic communication. The system includes a main cavity, a self-injection locked feedback module, and an erbium-doped fiber amplifier. The main cavity internally includes a composite ring cavity filter for selecting longitudinal modes. This composite ring cavity filter is sequentially connected to a polarization controller, a first erbium-doped fiber, a first wavelength division multiplexer, a second erbium-doped fiber, and a first uniform fiber grating via a first circulator. The output of the first uniform fiber grating is connected to the input of a first fiber coupler. One output of the first fiber coupler is sequentially connected to a fiber delay line and a Faraday rotator in the self-injection locked feedback module, with the Faraday rotator rotating at a 90° angle. The other output of the first fiber coupler is connected to the input of the erbium-doped fiber amplifier. Through this structure, the present invention improves the stability of the laser system.

The utility model provides a transmission-type multichannel optical circulator, which comprises a first collimator array and a second collimator array, the first collimator array comprises a plurality of first collimators, and the second collimator array comprises a plurality of second collimators; a first light splitting device, a first wave plate group, a first Faraday rotation sheet, a second light splitting device, a second Faraday rotation sheet, a second wave plate group and a third light splitting device are sequentially arranged between the first collimator array and the second collimator array; wherein the first wave plate group is provided with two first wave plates, the two first wave plates cover different light paths of the first light splitting device, and the optical axes of the two first wave plates are different; the second wave plate group is provided with two second wave plates, the two second wave plates cover different light paths of the third light splitting device, and the optical axes of the two second wave plates are different. The transmission-type multichannel optical circulator is compact in structure and low in production cost.

A bismuth-substituted rare earth iron garnet single crystal suitable for Faraday rotators and optical isolators with reduced insertion loss due to suppressed valence fluctuation of Fe ions is provided. The bismuth-substituted rare earth iron garnet single crystal of the present invention is characterized by the composition formula (GdaLnbBicMg3−(a+b+c))(FedGaeTifPt5−(d+e+f))O12. In the composition formula above, 0.02≤f≤0.05, 0.02≤{3−(a+b+c)}≤0.08, and −0.01≤{3−(a+b+c)}−{f+5−(d+e+f)}≤0.01. Ln is a rare earth element and may be selected from Eu, Dy, Gd, Ho, Tm, Yb, Lu, and Y.

A free space optical communications terminal (100) including an optical arrangement of a quarter-wave plate (105), a Faraday rotator (110), a polarisation splitter (115), a first arm (120) comprising a receiver (126) and a transmitter (128), and a second arm (130) comprising a component (132) configured to utilise a received beam. The optical arrangement apportions a circularly polarised beam between the first and second arm.

An optical isolator according to an aspect of the present disclosure includes a first polarizer through which incident light transmits, a Faraday rotator configured to rotate the polarization direction of the light, and a second polarizer through which the light transmits. The Faraday rotator includes a calcium fluoride crystal. When a, b, and c axes are the [001], [100], and [010] crystallographic axes, respectively, and x, y, and z axes are obtained by rotating the three axes by a first angle of 40° to 50° about the c axis and by a second angle of 45° to 75° about the b axis rotated by the first angle, the z axis is parallel to the propagation direction of the light, and the calcium fluoride crystal is disposed such that the transmission axis of the first polarizer and the x axis have an angle difference of 0° to 45°.

The invention discloses a light source phase noise suppression system based on self-reference demodulation of a 3 * 3 coupler. The light source phase noise suppression system comprises an internal modulation laser; a first optical circulator; a 3 * 3 coupler; first, second and third Faraday polarizers; an optical isolator; a second optical circulator; the first input end of the second 1 * 2 coupler is coupled to the third port of the second optical circulator, and the second input end of the second 1 * 2 coupler is coupled to one port of the first 1 * 2 coupler to receive a reflection signal of the third Faraday polariscope; the first photoelectric detector, the second photoelectric detector and the third photoelectric detector are respectively coupled to a third port of the first optical circulator and two ports of the 3 * 3 coupler; the fourth photoelectric detector is coupled to the output end of the second 1 * 2 coupler; and the resolving unit is used for receiving the electric signals output by the four photoelectric detectors. According to the light source phase noise suppression system based on self-reference demodulation of the 3 * 3 coupler, an additional reference probe or an additional shunt does not need to be introduced, and the volume cost of the system is reduced.

The invention provides a phase modulator half-wave voltage test system, which belongs to the technical field of phase modulator performance test, and is characterized in that an optical signal enters a polarizer to be converted into linearly polarized light, and light energy is uniformly distributed to two orthogonal polarization modes of a fast axis and a slow axis through a polarization-maintaining tail fiber of the phase modulator; a preset four-state square wave modulation signal is loaded to a phase modulator, a modulated optical signal is converted into left-handed and right-handed circularly polarized light through a quarter-wave plate, the left-handed and right-handed circularly polarized light is transmitted to a Faraday rotating mirror and then is reflected, the rotation directions of the left-handed and right-handed circularly polarized light are interchanged, the left-handed and right-handed circularly polarized light is returned along an original path, interference occurs at a polarizer, and the polarization direction of the polarization is changed. And the interference light signal is finally transmitted to the signal processing module for signal acquisition and processing. According to the invention, in-situ accurate measurement of the half-wave voltage of the phase modulator is realized, an original optical path structure does not need to be disassembled or damaged, and the method is suitable for performance monitoring and intelligent diagnosis of phase modulators in various high-precision optical fiber sensing systems, and has a wide application prospect.

Provided is an optical circulator that makes it possible to easily detect damage to an element of the optical circulator.　This optical circulator 1 is characterized by comprising a first port P1 through which light enters, a second port P2 that is opposite the first port P1 and emits light that has entered through the first port P1, a third port P3 that is provided so as not to be on a straight line that connects the first port P1 and the second port P2 and emits light that has entered through the second port P2, a first polarizer 5 that is provided on the first port P1 side, a second polarizer 6, a third polarizer 7 that is provided on the second port P2 side and sandwiches the second polarizer 6 with the first polarizer 5, a Faraday rotator 8 that is provided between the first polarizer 5 and the second polarizer 6, a 1 / 2 wavelength plate 9 that is provided between the second polarizer 6 and the third polarizer 7, and a light-emitting part 3, the third polarizer 7 and the 1 / 2 wavelength plate 9 being provided such that a portion of light that has entered through the first port P1 and has passed through the first polarizer 5, the Faraday rotator 8, the second polarizer 6, and the 1 / 2 wavelength plate 9 to enter the third polarizer 7 is reflected to become reflected light that can be extracted by the light-emitting part 3.

The present application relates to the field of optical technology, a Fizeau interferometer with high interference contrast by adapting the reflectivity of detection surface, comprising laser light source, 1 / 2 wave plate, converging lens group, illumination diaphragm, polarization beam splitter, collimating lens group, Faraday rotator and polarization reference mirror group arranged in sequence along the first light path direction; further comprising imaging diaphragm, imaging lens group and ccd camera arranged in sequence along the second light path direction; the 1 / 2 wave plate is installed on a rotating mechanism for adjusting the fast axis angle; the first light path direction is the same as the transmission optical axis direction of the polarization beam splitter, and the second light path direction is the same as the reflection optical axis direction of the polarization beam splitter. The maximum light intensity of the interference signal is jointly adjusted by the output power of the laser light source and the 1 / 2 wave plate; the contrast of the interference signal is adjusted by the Faraday rotator.