73 results about "Resonance line" patented technology

The invention relates to a preparation method for a micro-electro-mechanical system (MEMS) atomic vapor chamber and the atomic vapor chamber. The chamber is prepared by bonding a Pyrex glass sheet, a silicon wafer and a Pyrex glass sheet by an anodic bonding technology; the Pyrex glass sheet is taken as a window of the chamber; a chamber space is formed by etching or corroding the silicon wafer; paraffin packaged alkali metal such as rubidium (Rb) or cesium (Cs) is put into the chamber, and buffer gas with appropriate pressure is introduced simultaneously; paraffin is taken as a packaging material of the alkali metal, so that active alkali metal is isolated from oxidants such as oxygen, water vapor and the like in an environment; the paraffin is also used as a plating material of the chamber, so that collision between Rb or Cs atoms and a chamber wall is slowed down; and a CO2 laser is used for melting the paraffin to release the alkali metal, so that a uniform paraffin plating is formed on the chamber wall. The problem of long-term drift caused by reaction residues generated by a field preparation mode is solved, the collision between the Rb or Cs atoms and the chamber wall is slowed down, and the contrast of atomic resonance line width of the alkali metal is improved.

A magnetic oscillating device including a first magnetic resonance layer with a first magnetic resonance frequency f₁, a second magnetic resonance layer with a second magnetic resonance frequency f₂ higher than the first magnetic resonance frequency f₁, a nonmagnetic layer sandwiched between the first magnetic resonance layer and the second magnetic resonance layer, and a pair of electrodes which supplies a current perpendicularly to film planes of the first and second magnetic resonance layers, in which a difference (f₂−f₁) between the two magnetic resonance frequencies is larger than half a resonance line width of the first magnetic resonance layer, and a ratio of the two magnetic resonance frequencies f₂/f₁ is 1.6 or less.

The invention discloses a method used for on-line measurement of density of alkali metal in atom magnetometer air chambers at SERF (spin-exchange relaxation free) states. According to the method, an atom magnetometer is provided with a weak background magnetic field and low frequency stage horizontal linear frequency modulated signals, a data collecting card is used for collecting response signals of the atom magnetometer in frequency sweep time; fast Fourier transform is adopted so as to obtain a magnetic resonance curve in a frequency domain, the resonance line width and the resonant frequency of the magnetic resonance curve are obtained via calculation; the background magnetic field is changed so as to obtain a plurality of resonance line widths and resonant frequencies, quadratic curve fitting of the resonance line widths and the resonant frequencies is carried out so as to obtain spin exchange time; and at last the density of alkali metal in atom magnetometer air chambers at the current temperature can be obtained via calculation. The method can be performed at maintained SERF states, on-line measurement of the density of alkali metal in the air chambers can be realized only using the SERF magnetometer; excellent frequency resolution ratio of linear frequency signals can be achieved at low frequency range (1kHz or lower); and the method is suitable for low frequency scanning range required by SERF magnetometer weak magnetic field.

The invention provides a frequency calibration circuit and a method thereof. The frequency calibration circuit comprises a phase lock loop circuit, an M-dividing divider for generating a plurality of phase signals, a sampling circuit for sampling on the rising edges of the phase signals, a first counter for counting reference frequency signals, a second counter counting first phase signals, a logical control circuit for comparing a count value with a target count value to obtain a minimum difference value, and looking up a control bit of a voltage-controlled oscillator through the difference value, and a comparison circuit for judging whether the control voltage of the voltage-controlled oscillator is in a set range or not. The method comprises the following steps: sampling the reference frequency signals to obtain a total count value; comparing the total count value with a target count value; selecting a next resonance line according to a binary lookup flow till binary lookup ends; and outputting a resonance line corresponding to a minimum error in order that the output frequency of the voltage-controlled oscillator reaches a required value. Through adoption of the frequency calibration circuit and the method thereof, the speed and accuracy are increased, and the requirement on the working frequency of a digital circuit is lowered, so that a design method is simplified.

The invention discloses a small-line-width low-loss microwave ferrite material, which has a main phase of a garnet structure and a chemical formula of Y3-2xCa2xVxInyMnzFe5-x-y-zO12 or Y3-xCaxGexInyMnzFe5-x-y-zO12, wherein x is more than or equal to 0.01 and is less than or equal to 1.0, y is more than or equal to 0.08 and is less than or equal to 0.5, and z is more than or equal to 0.01 and is less than or equal to 0.06. The invention also provides a method for preparing the small-linewidth low-loss microwave ferrite material. The manufacturing process flow of the method comprises the following steps: 1) calculating and weighing raw materials according to the chemical formula; 2) performing primary wet method ball milling on the raw materials; 3) performing primary sintering; 4) performing secondary wet method ball milling; 5) performing drying and granulating; 6) performing press forming; and 7) performing secondary sintering. The small-linewidth low-loss microwave ferrite material has the advantages of smaller resonance line width (deltaH) and lower dielectric loss (tgdeltae), greatly improves stability and reliability, and enlarges application range; a microwave device made from the small-line-width low-loss microwave ferrite material has better quality; besides, the method has a reasonable process, so that the production cost is further reduced.

In an apparatus using optically excited atomic media, such as an atomic frequency standard, a source providing a controlled emission of light for exciting the D₁ and/or D₂ resonance lines of an alkali gas, such as rubidium or cesium, is controlled by an output generated by digital electronics from the light intensity signal of a light sensor for light transmitted by the alkali gas, an output for representing ambient temperature, and a light intensity-ambient temperature algorithm to substantially eliminate changes in light intensity due to light source aging for the purpose of reducing changes in temperature sensitivity of the apparatus as a function of time and the light-shift contribution to the frequency aging of the standard.

The invention discloses a small-line-width high-Curie-temperature microwave ferrite material of which the main phase is a garnet structure. The microwave ferrite material is characterized in that the chemical formula is Y[3-x]CaxSnxMnyFe[5-x-y-z]O12, wherein 0.05<=x<=0.2, 0.02<=y<=0.06, 0.14<=z<=0.24, and z is a technical amount of iron deficiency. The preparation method of the small-line-width high-Curie-temperature microwave ferrite material comprises the following steps: (1) after designing the formula, carrying out stoichiometric calculation and weighing raw materials; (2) carrying out primary wet-process ball milling; (3) presintering; (4) secondary wet-process ball milling; (5) drying and granulating; (6) carrying out pressure molding; and (7) sintering. The material has the advantages of smaller resonance line width DeltaH, higher Curie temperature Tc, high saturation magnetization temperature stability, compact structure and low cost; and the device prepared from the material has the advantages of low loss and stable performance, and is suitable for application and popularization.

The invention discloses a periodic-array local plasma resonance sensor. The sensor comprises a substrate and a plurality of sensor units which are arranged on the surface of the substrate to form a periodic array structure. The periodic-array local plasma resonance sensor has the advantages of high sensitivity of sensing, low resonance line width, high signal modulation depth and large-scale detection angle tolerance.

The present invention provides a guided mode resonance grating narrow line width vertical-cavity surface emitting laser and a preparation method thereof. According to the present invention, a guided-mode resonant effect of a micro-nano grating is utilized, and a sub-wavelength guided-mode resonant microcavity structure of high reflection and narrow resonance line width is used as a part of the vertical-cavity surface emitting laser, thereby achieving the purposes of narrower laser line width, wider high reflection bandwidth, smaller size and stable polarization control. According to the present invention, by utilizing the guided-mode resonant effect of the micro-nano grating, and by the equivalent medium theoretical calculation, a weak modulated sub-wavelength grating guided-mode resonant microcavity structure of which the resonant wavelength is 852 nm is designed, and a wall used for controlling the mode line width is added between a grating layer and a waveguide layer, so that the mode line width can reach 1 nm or less. Relative to a conventional VCSEL, the narrow line width vertical-cavity surface emitting laser has the narrower laser line width, the wider high reflection bandwidth, the smaller size and the stable polarization control.

An electron paramagnetic resonance imaging (EPRI) system includes a resistive magnet driven by a power supply such as a power supply module to generate radio frequency signals in a substantially coherent polyphase perfect sequence scheme. The EPRI system further includes image acquisition and processing electronics configured to generate, acquire, quantify and map pO2 information associated with a free radical agent in vivo and having a resonance line width that is sensitive to oxygen and in response to the radio frequency signals without imparting harmful heating effects to a corresponding human or animal body.

In a method and device to detect interference signals in magnetic resonance spectroscopy signals a comparison signal is computationally reconstructed that optimally approximates a measured, detected magnetic resonance spectroscopy signal. The comparison signal forms spectral components of resonance lines of the measured magnetic resonance spectroscopy signal. A residual is calculated from the difference of the two signals (comparison signal and magnetic resonance spectroscopy signal) in the frequency representation. The interference signals are determined from the residual.

The invention relates to a compact photon structure capable of realizing various resonance line types based on a micro ring cavity. The compact photon structure comprises a straight waveguide (1), a micro ring cavity (2) and a substrate (4), and is characterized in that the straight waveguide (1) and a micro ring cavity (2) are located on the substrate (4), and a gap is reserved between the straight waveguide (1) and the micro ring cavity (2); the straight waveguide (1) is provided with two air holes; and the straight waveguide (1) and the micro ring cavity (2) are equal in thickness d and width w, and the straight waveguide (1) and the micro ring cavity mutually adopt lateral coupling. The beneficial effects comprise that the photon structure is compact, not only can realize various resonance line types at a specific resonant wavelength of a transmission spectrum of a waveguide-micro ring cavity coupling structure, but also has the characteristic at multiple resonant wavelengths in a wide band range, and can meet the demand of realizing various applications by using the single micro ring cavity.

A plasma display device, which is capable of improving a discharge efficiency of a plasma display panel by increasing a partial pressure of Xe. When the partial pressure of Xe is increased, a proportion of (Xe-Xe)* dimer emitting a 147 resonance line is higher than that of Xe* monomer emitting a 173 nm molecular beam. Particularly, when the partial pressure of Xe is above 10%, the discharge efficiency is improved by setting a frequency of a sustain discharge pulse applied to scan electrodes and sustain electrodes alternately during sustain period above 300 kHz.

The invention provides a structure of coupled local surface plasma and waveguide mode. The structure comprises a substrate, a waveguide layer manufactured on the substrate, and an Au particle layer manufactured on the waveguide layer. The structure can effectively reduce full width at half maximum of resonance line, thereby improving figure of merit (FOM) of sensors.

The invention discloses a garnet ferrite material with a high dielectric constant and a preparation method thereof. The chemical formula of the garnet ferrite material is Y3-a-b-(2c+d+e)GdaBibCa2c+d+eVcZrdSneMnfAlgFe5-c-d-e-f-g-delta O12, a is greater than 0 and less than or equal to 1.2, b is greater than or equal to 0.6 and less than or equal to 1.5, c is greater than 0 and less than or equal to0.6, d is greater than 0 and less than or equal to 0.7, e is greater than 0 and less than or equal to 0.7, f is greater than 0 and less than or equal to 0.15, g is greater than 0 and less than or equal to 0.5, and delta is greater than 0 and less than or equal to 0.3, the delta is process iron deficiency amount. The invention further provides a preparation method of the material. The garnet ferrite material with the high dielectric constant has the temperature characteristics of narrow resonance line width delta H and excellent saturation magnetization intensity Ms, can effectively reduce thesize of a central junction region of a microwave ring/isolator, and meets the miniaturization design requirement of a device.

A method of investigating a sample (1) having an absorption within an infrared spectral range of interest, comprises the steps of creating measuring light (2) with a light source device (10), wherein the measuring light (2) includes wavelengths covering the infrared spectral range, directing the measuring light (2) through the sample (1) to a detector device (20) with a plurality of detector units (21), (21) each of which comprising an infrared sensitive sensor section (22) and an associated metamaterial resonator section (23) having a specific spectral resonance line (3), wherein the spectral resonance lines (3) of the resonator sections (23) have different frequencies within the infrared spectral range, wherein the measuring light (2) is transmitted through the sample (1) to the resonator sections (23) and subsequently sensed by the sensor sections (22), wherein an output of each of the sensor sections (22) depends on the absorption of the sample (1) at the frequency of the spectral resonance line (3) of the associated resonator section (23), and providing at least one absorption characteristic of the sample (1) on the basis of the output of the sensor sections (22), wherein the sample (1) is arranged for providing near field coupling of electronic states of the sample (1) and photonic resonator states of the resonator sections (23), wherein, for each of the resonator sections (23), a resonance line attenuation is created, which is determined by a complex refractive index of the sample (1) at the frequency of the spectral resonance line (3) of the resonator section (23), and the output of each of the sensor sections (22) is determined by the resonance line attenuation of the associated resonator section (23). Furthermore, a spectrometer apparatus (100) for investigating a sample (1) is described, which has an absorption within an infrared spectral range of interest.

The invention discloses a high-sensitivity magnetic field measurement method based on electron spin magnetic resonance linewidth narrowing. The method comprises the following steps: step 1, setting adriving light frequency; step 2, performing electron spin magnetic resonance line width measurement; step 3, optimizing the power of driving light; and step 4, optimizing the electron spin density. The high-sensitivity magnetic field measurement method has the beneficial effect that the optically polarized electron spin ground state low ultrafine energy level is driven by high power; magnetic resonance linewidth narrowing is realized by improving the atomic polarizability, so that the magnetic field measurement sensitivity is improved; and the method is particularly suitable for a high-densityand small-size buffer gas chamber. On the one hand, the consistency of the buffer gas chamber is good, the yield is high, and the high-sensitivity magnetic field measurement method is suitable for engineering application; and on the other hand, the whole volume of the atom magnetometer is greatly reduced by adopting a high-density and small-volume air chamber, so that the atom magnetometer is applied to the hot spot fields of magnetoencephalogram, unmanned magnetic anomaly detection and the like; and the application range of the electron spin magnetic field measurement method is widened.

The embodiments of the invention provide a method and a device for realizing a CPT atomic frequency standard. By a perpendicular intersection of a laser emitted by a first VCSEL through a polarizer and a laser emitted by a second VCSEL through a half-wave plate in a polarization spectroscope, the first VCSEL and the second VCSEL are enabled to generate linearly polarized light coherent polychromatic light, and the linearly polarized light coherent polychromatic light interacts with the atoms in absorption bubbles, so that the output of the CPT atomic frequency standard is realized and the atoms are prevented from being accumulated in a polarization dark state. In addition, the power of a microwave signal coupled on an input current of the each VCSEL is relatively low, so that the total energy of all sidebands of the laser emitted by the each VCSEL is lower than a threshold value, the energy of the laser not participating in the interaction with the atomic is enabled to be relatively low, and interference and noise of a CPT resonance line are reduced. By the method and device, a contrast ratio of the CPT resonance line can be increased, and the stability of the CPT atomic frequency standard is improved.

The present invention describes a magnetic resonance imaging method wherein spatially resolved frequency sensitive image data are collected by means of free precession sequences employing very small radio frequency (RF) excitation pulses per unit time which result in highly frequency selective steady-state signals dominated by linear properties of the system, for which the superposition principle holds. By appropriate linear combination of steady state signals of N different frequencies, N resonance lines can be acquired simultaneously. This method allows spectroscopic recordings with very low RF power deposition which renders the method suitable for applications at high static magnetic field strengths.

A balance-unbalance conversion element that easily adjusts the phase balance between two balance signals. The balance-unbalance conversion element includes a dielectric substrate and an electrode pattern on a surface of the dielectric substrate. The electrode pattern includes a first ¼-wavelength resonance line coupled to a first balance terminal; a second ¼-wavelength resonance line coupled to a second balance terminal; a ½-wavelength resonance line having a first open end coupled to an unbalance terminal and the first ¼-wavelength resonator and a second open end coupled to the second ¼-wavelength resonator; and a balance characteristic adjustment electrode having a tip end opposed to a side of the ½-wavelength resonance line and a base end electrically coupled to a ground electrode. A center line of the electrode pattern on the surface of the dielectric substrate and the center of the tip end of the balance characteristic adjustment electrode are separated from each other.