38results about How to "Large tunable range" patented technology

An RE doped optical fibre with dual glass clad layers, that is, coaxial internal and external clad layers. The fibre core is made of phosphate glass system. The internal clad layer is made of phosphate (or silicate) glass system. Its preparing process includes choosing the raw glass materials for fibre core and internal clad layer, melting, preparing prefabricated rod, and drawing. Its advantages are high concentration of doped RE ions, and gain, big excited emitting area, wide tunning range and low cost.

The invention belongs to the antenna technical field and specifically relates to a frequency-and-pattern-reconfigurable antenna based on a liquid crystal material. The frequency-reconfigurable antenna comprises a liquid crystal phase shifter, a liquid crystal microstrip antenna and a one-to-four power divider. By combining the electrical regulation and control characteristic of the liquid crystal material and the design of the frequency-and-pattern-reconfigurable antenna, the frequency-and-pattern-reconfigurable antenna based on the liquid crystal material is produced, so that the frequency of the antenna can realize continuous regulation, tuning range is large and wave beams are deflectable; and practical application of the frequency-and-pattern-reconfigurable antenna in the aspects of miniaturization and broadband is improved.

The present invention discloses a fusion welding method for glass fiber with different components. Air flow is used for vertically blowing discharge arc to form a temperature gradient field. So optical fibers with different hot melting properties are melted at the same time and the permanent connection is realized. Two optical fibers are placed symmetrically between a pair of discharge electrodes. The optical fiber with low melting temperature is placed in a vent pipe or the vent pipe is placed parallel to the optical fiber with low melting temperature. Through air blowing arc, the size of the air flow is adjusted and the suitable temperature gradient field is obtained. The temperature field is capable of resulting in that the optical fibers with different melting temperatures placed at the two sides of the electrode show the melting state at the same time. A connecting joint with low loss and high intension is formed after the optical fibers being contacted. The present invention has the advantages that the tunable range is big and the optical fibers with different thermal properties which can not be fusion jointed by the traditional method can be fusion jointed by the present invention.

The invention discloses a variable optical attenuator based on liquid crystal cladding polymer optical waveguide. The variable optical attenuator comprises a silicon base, a bottom electrode, a silica lower cladding, a polymer optical waveguide core layer, a liquid crystal lower directional layer, a liquid crystal partition layer, a liquid crystal layer, a liquid crystal upper directional layer and a top electrode. Transmitting light can be transmitted with low loss in the polymer optical waveguide core layer under the condition of no impressed voltage; refractive index of the liquid crystal layer is gradually increased when the impressed voltage is gradually increased; and the transmitting light is gradually spread into the liquid crystal layer acting as the waveguide cladding layer and is not served as a guide film to transmit, so that loss is increased and functions of the variable optical attenuator can be realized. The variable optical attenuator based on the liquid crystal cladding layer polymer optical waveguide has the advantages that the variable optical attenuator has a compact structure and is convenient and easy to manufacture, do not have limits to long wavelength, and working bandwidth is large, and practical requirements in the photo-communication field, the integrated optics field and the like can be met.

The invention discloses a chirp fiber grating comb-shaped filter based on the electromodulation, belonging to the tunable fiber grating filter field, characterized by comprising resistance wires, a variable resistance, a linear chirp fiber grating, a thermal insulation plate, a plurality of fine V-shaped slots on the thermal insulation plate, a fiber fixing frame, an anode, a cathode, a bottom plate and a fiber. The linear chirp fiber grating is combined with the external heat source formed by the resistance wire, the temperature distribution on the fiber grating is changed by a partial heating way, thus compared with the left area and the right area, one of a plurality of partial areas in the axial direction of the chirp fiber grating has bigger temperature abrupt change, the phase shift is generated, therefore the filter has wide reflecting band with one or a plurality of narrowband transmission windows. The variable resistance value can be changed to adjust the current passing through the resistance wires, thus controlling the temperature of the resistance wires and obtaining ideal phase shift amount and filtering effect. In addition, the number of the resistance wires is corresponding to the number of the transmission windows, thus the number of the resistance wires is changed to perform the single-wavelength, double-wavelength and multi-wavelength filtering, and the conversion is convenient, while the position of the resistance wires is changed to perform the wavelength tuning of the transmission windows. The filter is simple and direct, has variable filtering wavelength and channel number, the wavelength tuning range is limited by the chirp fiber grating bandwidth and can be tens of nanometer.

The invention provides a miniature bridge-type structure and a preparation method thereof. The miniature bridge-type structure comprises four cantilever beams, a metal bridge floor, four metal piers and a substrate. Each cantilever beam is of an L-shaped structure, one ends of the cantilever beams are fixedly connected with the metal piers in a perpendicular mode, and the other ends of the cantilever beams are connected with the metal bridge floor; the metal bridge floor and the cantilever beams are located in the same plane, the metal bridge floor is hung on the substrate through the four cantilever beams, and a cavity structure is formed between the lower bottom face of the metal bridge floor and the substrate. The method induces the steps of preparing the metal piers on the clean substrate surface, coating the substrate surface where the metal piers are formed with a sacrificial layer, carrying out photoetching treatment on the sacrificial layer, then removing the portions, on the tops of the metal piers, of the sacrificial layer to expose the tops of the metal piers, carrying out solidified treatment on the sacrificial layer, preparing the metal bridge floor on the solidified sacrificial layer, removing the portion, at the bottom of the metal bridge floor, of the sacrificial layer to form a cavity, and building the bridge-type structure. The miniature bridge-type structure is large in tuning range and good in bridge floor parallelism.

The invention belongs to the technical field of electronics, and discloses a voltage fluctuation resistant delay switch circuit based on rising edge sampling, which comprises an input interface Vin +and an input interface Vin-, an output interface Vout +, an output interface Vout-, a resistor R1, a capacitor C1, a voltage stabilizing diode VD1, a resistor R2, an NPN triode Q1, a resistor R4, a capacitor C2, a resistor R5 and a P-MOS tube MQ1 and a voltage stabilizing diode VD2; the first end of R1 is connected with Vin +, and the second end of R1 is connected with Vin- through the C1, the negative electrode of the VD1 is connected with the second end of the R1, the positive electrode of the VD1 is connected with the base electrode of the Q1 through the R2, and the emitter electrode of theQ1 is connected with the Vin-, the first end of R4 is connected with the collector electrode of the Q1, and the second end of R4 is connected with Vin + through the C2; the first end of R5 is connected with the second end of R4, and the second end of R5 is connected with Vin +; the source electrode of MQ1 is connected with Vin +, the grid electrode of MQ1 is connected with the second end of R4, and the drain electrode of MQ1 is connected with Vout +; the positive electrode of the VD2 is connected with the second end of the R1, and the negative electrode of the VD2 is connected with the drainelectrode of the MQ1, and Vin- and Vout- are grounded.

The invention discloses an ultra-broadband adjustable terahertz wave source system based on optical feedback modulation gain equalization, which includes an optical feedback modulation gain equalization unit, a longitudinal mode selection unit, a ring resonator unit and a frequency mixing unit; the optical feedback modulation gain The balance unit is connected to one end of the longitudinal mode selection unit, the other end of the longitudinal mode selection unit is connected to the ring resonator unit, the output end of the ring resonator unit is connected to the frequency mixing unit, and the input end of the ring resonator unit is also connected to the pump light source . The invention introduces the optical feedback technology into the optically generated terahertz wave system, which can realize the generation of terahertz waves with low phase noise, high performance, high efficiency, ultra-narrow line width, and ultra-wideband; the system development cost is low, the signal spectrum purity is high, The tunable range is large, and there is no need to introduce complex mechanisms such as spatial hole burning, polarization hole burning, and nonlinear effects into the system.

The invention discloses a digital modulation signal source based on a microwave photon technology. In a digital modulation signal source composed of a mode locked laser 101, a luminous intensity modulator 102, a light polarization modulator 103, a tunable polarization correlation light comb filter 111, a tunable light band pass filter 108, a linearity dispersion medium 109 and a photoelectric detection unit 110, the tunable polarization correlation light comb filter 111 is formed by connecting a light circulator 104, a polarization beam splitter 105, programmable polarization mold dispersion units 106-1 and 106-2, and 45-degree Faraday rotators 107-1 and 107-2 in a specific mode, such that independent tunable comb filtering can be performed on mutually vertical linear polarization states, digital modulation signals with different modulation rates, different carrier wave frequencies, different modulation modes and different duty ratios are generated, and the digital modulation signal source can be applied to multiple important fields such as the transmitting end of a super-speed network, a radio-on-fiber system, a military radar and the like.

The invention relates to the field of optical remote sensing measurement technologies, in particular to a gas composition telemetering method based on tunable mid-infrared laser. The method is implemented through the steps that the tunable mid-infrared laser transmitted by a laser device (1) is subjected to beam expansion by a telescope collimator (2) and is transmitted to penetrate through a target region, beams are reflected back in parallel by a backward reflector array (3) and are converged by a detection telescope onto a semiconductor-refrigerated photoelectric detector (4), an electric signal is subjected to frequency selection and amplification through a main control circuit (5) and then passes through an A/D converter (6) after the signal-to-noise ratio is increased, and a computer(7) collects and records mid-infrared absorption spectrum data in an open path. Through independently-developed difference calculation software, whether a target gas exists or not and a concentrationvalue are given, and the target gas existing condition and the concentration value are displayed through a displayer (8).

The invention discloses a pulse fiber laser seed source and a pulse adjusting method. The seed source generates a quadrilateral pulse through a modulator outside a first resonant cavity, and the modulator can also be used as a Q switch in a second resonant cavity, so that a Gaussian or Gaussian-like pulse is generated, that is, in the same seed source, through adjusting the pumping power, the pulse shape can be adjusted; and on the other hand, when the modulator outside the first resonant cavity generates quadrilateral pulses, the pulse width is controlled according to the switching time of the modulator, the pulse repetition frequency is controlled according to the repetition frequency of the modulator, the pulse width and repetition frequency change is more flexible, and the tunable range is larger.

The invention belongs to a light-beam-controllable nanowire laser based on patterning growth, belongs to the fields of micro-nano optics and optical nanomaterial, and in particular relates to the nanowire laser. The light-beam-controllable nanowire laser comprises a substrate, an isolating medium, a patterning groove formed in the isolating medium and a nanowire array growing in the groove. The light-beam-controllable nanowire laser combines the luminous characteristic of the nanowire with a micro-nano light beam regulating and controlling lens; a patterning region for allowing the nanowire to grow is manufactured for realizing the light beam regulation and control, so that the light beam regulation and control of collimation, focusing and the like of the emergent light of the nanowire is realized; the shortcomings of severe scattering, low energy utilization rate and the like of the nanowire luminance are overcame; and the actual applications of the nanowire laser in small-sized and integrated optical devices are improved.