41results about How to "Reduce half wave voltage" patented technology

The making process of lithium niobate modulator includes making substrate with lithium niobate crystal with proper crystal cutting direction and electric field utilizing direction; making light waveguide on the lithium niobate crystal; making modulating electrodes including central signal electrode and earth electrode and to form push-pull structure with the light waveguide; making microstrip matching structure in the input and output of the modulating electrodes; and setting buffering layer structure between the modulating electrode and light waveguide. Owing to the smart design of the modulating electrodes, the light waveguide and the matching structure in between, the lithium niobate modulator has high modulating rate, low insertion loss, high extinction ratio, low hemi-wave voltage, less electric reflection, and high reliability.

The invention discloses an all-fiber electro-optical modulator based on graphene materials and a method of the all-fiber electro-optical modulator. The all-fiber electro-optical modulator based on the graphene materials comprises a single mode fiber, a silicon dioxide groove-type substrate, an Al2O3 transition thin layer and a graphene membrane, wherein the single mode fiber is arranged on the silicon dioxide groove-type substrate and fixed through sealed epoxy glue, a groove is formed in the single mode fiber, the Al2O3 transition thin layer is arranged in the groove, and the graphene membrane is arranged on the Al2O3 transition thin layer. Conductivity performance of graphene is changed through change of voltage applied on a metal electrode, therefore an imaginary part or a real part of an effective refractive index of a graphene composite layer structure is changed, and an electric absorption strength modulator or a phase modulator is achieved. The all-fiber electro-optical modulator based on the graphene materials and the method of the all-fiber electro-optical modulator can achieve design of the all-fiber electro-optical modulator, and have the advantages of being tiny in size, little in power consumption, low in insertion loss, high in modulating speed, beneficial for optical integration and the like. In addition, due to the fact that additional optoelectronic devices are not introduced, the all-fiber electro-optical modulator based on the graphene materials and the method of the all-fiber electro-optical modulator are suitable for being used in an all-fiber communication system and a dense wavelength division multiplexing (DWDM) system.

The present invention discloses a high-speed modulator which comprises an optical waveguide structure and a traveling wave electrode structure, the optical waveguide structure comprises a first optical waveguide arm and a second optical waveguide arm, a traveling wave electrode comprises a grounding electrode and a signal line, and the signal line applies electric fields or voltages in opposite directions to the first optical waveguide arm and the second optical waveguide arm. The first optical waveguide arm and the second optical waveguide arm are both of a folding structure, and the signal line is folded along with the first optical waveguide arm and the second optical waveguide arm, so that an electric field or voltage applied to the first optical waveguide arm and the second optical waveguide arm is kept unchanged. Or the electric field or the voltage applied to the first optical waveguide arm and the second optical waveguide arm is synchronously changed. Compared with the prior art, the device has the advantages that the folding structure of the optical waveguide is matched with the ground-signal-ground coplanar waveguide traveling wave electrode structure, modulation addition of light in different sections of the waveguide is achieved, the longer phase shift waveguide length can be achieved within the limited device length, and meanwhile it can be ensured that the bandwidth meets the application requirement.

The invention relates to an all solid-state 455nm pulsed laser based on a neodymium-doped fluorinated lutetium lithium crystal, which is suitable for underwater laser communications. The all solid-state 455 nm pulsed laser is characterized by comprising a laser diode output with tail fibers, and a pump optical coupling system, a laser cavity and a multiple frequency crystal are sequentially arranged along the advanced direction of the laser diode outputting a laser, wherein the laser cavity comprises an Nd: LiLuF crystal and an electrooptic Q-crystal. The invention has the characteristics of compact structure, small size, long life and stable working.

The invention discloses a loading strip-structure silicon/PLZT hybrid waveguide-based Mach-Zehnder electro-optical modulator. The silicon/PLZT hybrid waveguide-based Mach-Zehnder electro-optical modulator comprises a waveguide, an MMI-based Mach-Zehnder interference structure and a coplanar waveguide electrode structure, wherein the waveguide comprises a silicon core layer, a ferroelectric thin film lower coating layer and a silicon dioxide upper coating layer, and the coplanar waveguide electrode structure is designed in order to achieve high-speed electro-optical modulation. The modulator sequentially comprises a coplanar waveguide electrode, the silicon dioxide upper coating layer, a silicon waveguide layer, a PLZT lower coating layer and an NST substrate from top to bottom, wherein thecoplanar electrode can be used for loading a radio frequency signal and loading the radio frequency signal to an optical wave to achieve electro-optical modulation. By the silicon/PLZT hybrid waveguide-based Mach-Zehnder electro-optical modulator, high modulation depth, low transmission loss and high modulation bandwidth can be achieved, and the silicon/PLZT hybrid waveguide-based Mach-Zehnder electro-optical modulator can be applied to an integrated high-speed microwave optical network.

The invention relates to a Z-tangent LNOI electro-optical modulator capable of improving modulation efficiency and an application thereof. The Z-tangent LNOI electro-optical modulator comprises a substrate, an insulating layer, a waveguide core layer, an upper cladding layer, a signal electrode and a ground electrode, wherein a bottom of the substrate is provided with a groove; the insulating layer is disposed on the substrate; the waveguide core layer is arranged on the insulating layer, and a tangential direction of the waveguide core layer is Z-tangent; the upper cladding layer is arrangedon the waveguide core layer, is used for forming a refractive index difference with the waveguide core layer so as to limit transmission of an optical field, and is used as a support structure of an upper-layer electrode; the signal electrode is arranged at the position, corresponding to an optical waveguide, of the cladding layer and used for applying an electric signal to form an electric fieldto perform electro-optical modulation on light in the waveguide core layer; and the ground electrode is arranged in the groove, and an electric field between the ground electrode and the signal electrode is along an optical axis direction of the Z-tangent LN. In the invention, ultra-efficient electro-optical modulation of near 100% of the electric field to an optical field is realized so that a half-wave voltage of the modulator is greatly reduced, and power consumption of the modulator is reduced.

The invention discloses a lithium niobate film electro-optical modulator chip. A Y-branch waveguide, a waveguide optical path of a radio frequency modulation part and a waveguide optical path of a bias voltage control part are separated in space, and a 90-degree bent waveguide is used for connecting the waveguide optical paths, so that the length of the lithium niobate film electro-optical modulator chip can be remarkably shortened; in addition, the invention also provides a lithium niobate film electro-optical modulator, optical fibers serving as an optical input port and an optical output port are placed on the same side of a lithium niobate film electro-optical modulator chip, and the optical fiber port protection structure of the electro-optical modulator is placed on the same side of the device. The total length of the lithium niobate film electro-optical modulator can be effectively shortened.

The invention provides a reflection-type electro-optic phase modulator. The reflection-type electro-optic phase modulator comprises an electro-optic crystal, optical waveguide and modulation electrodes; the optical waveguide comprises n first light paths and n+1 second light paths, wherein n is greater than or equal to 2; the first light paths are sequentially arranged between a light-in surface and a light-out surface of the electro-optic crystal; the second light paths are connected between the light-out end of the ith first light path and the light-in end of the i+1 first light path, wherein i is equal to 1, 2, ..., n; high-reflection films are arranged at the connecting positions of the first light paths and the second light paths; the modulation electrodes are arranged on the two sides of the first light paths and the second light paths respectively. Compared with the prior art, according to the reflection-type electro-optic phase modulator, multiple Z-shaped light paths are adopted to form the optical waveguide, the action length of the electro-optic phase can be increased under the condition of not increasing the length of the electro-optic phase modulator, and half-wave voltage is lowered. Meanwhile, the structural size of the electro-optic phase modulator can be reduced, integration is easy, and the practicability of the electro-optic phase modulator is improved.

The invention discloses an electro-optical switch with low half-wave voltage, which comprises an insulating shell (201) and an electro-optic crystal (202); a pair of lateral surfaces of the crystal is plated with a metal conducting layer (203) respectively; an indium foil (204) is attached to the outside of the metal conducting layer; an inner metal electrode (205) is attached to the outside of the indium foil; and an external metal electrode hole (206) is reserved on the outside of the inner meal electrode. Through the electrode design, under the condition that the crystal has a certain length, when the electro-optical switch works, the ignition on the light-transmitting surface of the crystal caused by too close distance between the electrodes can be avoided so as not to influence the use of the switch or damage the light-transmitting surface of the crystal. The design effectively reduces the half-wave voltage of the electro-optical switch, prolongs the service life thereof and lowers the rigorous requirement on a switch driving power supply.

The invention provides a flexible lithium niobate film electroencephalogram detection chip and a device thereof, and the chip comprises a flexible lithium niobate substrate which is provided with an optical waveguide and a coplanar traveling wave electrode; a flexible support layer used for providing support for the flexible lithium niobate substrate; and an electrode arranged on the surface of the flexible supporting layer, and wherein the coplanar traveling wave electrode is electrically connected with the electrode. According to the invention, the flexible lithium niobate substrate and the flexible supporting layer have flexibility and can be better attached to the surface of the human brain; the flexible supporting layer is attached to the surface of the human brain, the electrodes of the flexible supporting layer make electrical contact with the human brain, the electrodes collect electroencephalogram signals and transmit the electroencephalogram signals to the coplanar traveling wave electrodes on the lithium niobate substrate, a weak electric field is formed between the coplanar traveling wave electrodes, the refractive index of the flexible lithium niobate substrate is changed, light is transmitted from the optical waveguide and passes through the modulation area with the changed refractive index, the optical path is changed, and the phase is changed during output. and long-distance transmission is light transmission, so that the long-distance transmission is not easily interfered by electromagnetic interference.

The invention discloses a method of making an optical planar waveguide. According to the invention, the cold welding process is used for bonding a laser crystal waveguide strip and an electro-optical crystal waveguide strip, excellent heat dissipation of a device at work can be achieved through accurate pressure control and selection of appropriate bonding material and substrate material, and internal stress accumulation due to uneven pressure can be eliminated. The making method is mature and high in consistency and can be batched.

The invention discloses a quantum key distribution system based on a reference frame-independent protocol, which uses light injection semiconductor lasers to generate quantum states with encoded information, replacing the traditional scheme of light sources and quantum state encoding modules. The photon time and phase difference information is generated by the light injection semiconductor laser in the quantum key encoding end, the first laser driver, the second laser driver, the pulse generation laser, the phase preparation laser, the first three ports in the quantum key encoding end The circulator forms the light injection semiconductor laser, and the second laser driver controls the phase preparation laser to inject the phase-modulated optical pulse with the pre-adjusted Δφ phase into the pulse generation laser, so that the pulse generation laser controlled by the first laser driver can generate a pair of phase difference Δφ Double-pulse signal light, thereby generating a pulse sequence with time and phase encoding information. The technical solution improves the anti-interference and coding rate of the system, and is beneficial to product integration and miniaturization.

The invention discloses a push-pull photonic crystal zipper cavity optical accelerometer with electromagnetic feedback. Light of a narrow linewidth light source is coupled through a spot size converter and enters a Y waveguide to realize light splitting, and light of a first branch end passes through a first input straight waveguide, a first upper nanometer micro beam and a first output straight waveguide and then is received by a first photoelectric detector. The light of the second branch end passes through a second input straight waveguide, a second lower nanometer micro beam and a second output straight waveguide and then is received by a second electric detector. The left driving electrode, the spring oscillator structure and the right driving electrode are respectively arranged between the first input straight waveguide and the second input straight waveguide, between the first upper nanometer micro-beam and the second lower nanometer micro-beam, and between the first output straight waveguide and the second output straight waveguide; the left driving electrode and the right driving electrode are electrically connected with the spring oscillator structure; and a permanent magnet is embedded in the ceramic base below the spring oscillator structure. According to the invention, high-resolution and large-bandwidth detection is realized, common-mode interference noise is suppressed, and the advantages of high integration level, large adjustable range and electromagnetic interference resistance are realized.