178results about How to "Oscillation stability" patented technology

A method and device selectively and reversibly disrupts the blood-brain barrier (BBB) in a selected volume of the brain without the need for exogenous agents. The method and device employ low intensity directed ultrasound (LODUS) that is safe, reduces the danger of cavitation and thermal tissue damage, and is able to expose small or large regions of the brain to achieve a desired therapeutic or prophylactic effect.

The present invention relates to a counterfeit-proof volume hologram multilayer structure capable of securely preventing a counterfeiter from replicating a volume hologram recorded therein. The multilayer structure comprises a transparent surface protective layer, a volume hologram layer, and an adhesive layer which are sequentially laminated and is characterized in that particles having particle diameter of 350 nm or more are dispersed in at least one of the transparent surface protective layer, the volume hologram layer, and the adhesive layer and that the refractive index ratio (nF / nB) is set to be not less than 1.05 or not greater than 0.95, wherein nF is the refractive index of the particles and nB is the refractive index of the medium in which the particles are dispersed, or characterized in that at least either the refractive index ratio (nP / nH) between the transparent surface protective layer and the volume hologram layer or the refractive index ratio (nH / nA) between the volume hologram layer and the adhesive layer is set to be not less than 1.08, wherein nP is the refractive index of the transparent surface protective layer, nH is the refractive index of the volume hologram layer, and nA is the refractive index of the adhesive layer.

Described is an infusion pump comprising electronic infusion regulating means with wired or wireless communication means and a power source, a medicament bag (7) and an infusion device, said infusion device being in fluid communication with said medicament bag (7) and comprising two valves (1, 2), a pressure cavity (4) provided between said two valves (1, 2) and a membrane (3) covering said cavity (4), wherein said infusion device comprises at least two active actuators, preferably either made of electroactive polymer so as to form a self actuating membrane (3) or made of shape memory alloy wire, one of said actuators being adapted to apply pressure to said membrane (3) for fluid displacement in said cavity (4), and the other of said actuators being adapted to operate one of said valves which is adapted to passively close in the flow direction of a fluid from said medicament bag (7) through the cavity (4), wherein the other of said valves is adapted to, in particular passively, close in a direction opposite to said flow direction.

The invention discloses a tunable laser system, a acousto-optic tunable filter that utilizes frequency offset compensation. Precision and stability of the output wavelength are realized by a wavelength lock; the wavelength lock utilizes two separated cavity laser beam to avoid using a beam splitter, which reduces requirements to space comparing to a tradition wavelength lock, and running is more stable, and assembly easier. The acousto-optic tunable filter comprises a acousto-optic crystal and a acoustic wave transducer that are bond on surface selected by a crystal to generate acoustic wave;an optical reflector is used for reflecting the diffracted ray back to the acousto-optic medium; because the two incident rays are opposite relative to the acoustic wave propagation direction, the frequency offset generated by the two diffraction is compensated. The invention can be used to produce wideband tunable laser system for various applications with different laser gain medium, acoustic wave drive frequency and acousto-optic crystal.

A Micro Electronic Mechanical System (MEMS) scan controller generating clock frequency and a control method thereof are disclosed. The MEMS scan controller is for a MEMS mirror in a bi-direction laser scanning units (LSU). By detecting resonant frequency of the MEMS mirror, the scan controller sends frequency modulation signal and amplitude modulation signal of the MEMS mirror to a bridge circuit of the MEMS mirror for adjusting and stabilizing the MEMS mirror. A clock signal corresponding to the resonant frequency of the MEMS mirror at the moment is also sent so that scan data is sent within the effective scanning window in forward direction / reverse direction. Thus high-precision scanning is achieved.

A photoelectric oscillator includes a laser beam projection unit; an optical modulator on an optical path extending from the projection unit, which optical modulator outputs a modulated signal or an optical signal containing a harmonic of the modulated signal and includes a modulation electrode whose resonant frequency band includes the frequency band of the modulation signal; a photoelectric converter for converting the output of the optical modulator to an electric signal; a feedback circuit for selecting from the radio-frequency electric signal obtained from the photoelectric converter an electric signal to be re-supplied to the optical modulator; and an output section for outputting an optical signal containing the modulation signal or a harmonic of the modulation signal or outputting the modulation signal or a harmonic of the modulation signal. A laser beam of sufficient intensity is input from the projection unit to produce a radio-frequency electric signal in the feedback circuit, and the radio-frequency electric signal or an optical signal containing the radio-frequency electric signal or the radio-frequency signal is output from the photoelectric oscillator.

An oscillator circuit comprises a piezoelectric vibrator, an amplifier device including inverters provided in a plurality of stages, and an inverter control device. The inverters provided in the plurality of stages includes a performance-variable inverter configured which is operational in both of an initial phase of oscillation startup and a post-startup phase where the oscillation is stabilized and capable of a variable performance depending on whether the initial phase of oscillation startup or the post-startup phase where the oscillation is stabilized, and an ON / OFF inverter which is operational in the initial phase of oscillation startup and disconnected in the post-startup phase where the oscillation is stabilized. The inverter control device have the performance-variable inverter and the ON / OFF inverter both operational and lowers the performance of the performance-variable inverter in the initial phase of oscillation startup, and the inverter control device disconnects the ON / OFF inverter and increases the performance of the performance-variable inverter in the post-startup phase where the oscillation is stabilized.

A magnetic recording head used for microwave-assisted magnetic recording includes: a main pole; a spin torque oscillator provided on the main pole, including a high-speed rotating magnetization layer in which the magnetization is rapidly rotated by a spin torque; a trailing shield provided on the spin torque oscillator; and a sub pole magnetically coupled to the trailing shield provided in a medium-facing surface, extending in a vertical direction to the medium-facing surface. Then, a non-magnetic electrode is provided on the outside of a trailing gap in which the spin torque oscillator is provided with respect to a magnetic material of the main pole, the trailing shield, or the sub pole, to prevent the line resistance variation due to the AMR effect or the eddy current. Thus, the variation of the current flowing to the spin torque oscillator can be controlled to achieve stable oscillation.

A wavelength tunable laser device includes: a laser cavity formed of a grating and a reflecting mirror including a ring resonator filter; a gain portion; and a phase adjusting portion. The grating creates a first comb-shaped reflection spectrum. The ring resonator filter includes a ring-shaped waveguide and two arms and creates a second comb-shaped reflection spectrum having peaks of a narrower full width than peaks in the first comb-shaped reflection spectrum at a wavelength interval different from that of the first comb-shaped reflection spectrum. One of the peaks in the first comb-shaped reflection spectrum and one of the peaks in the second comb-shaped reflection spectrum are overlapped on a wavelength axis, and a spacing between cavity modes is narrower than the full width at half maximum of the peaks in the first comb-shaped reflection spectrum.

Provided is a wavelength tunable external cavity laser comprising: a semiconductor laser diode that outputs multi-wavelength optical signals and is mounted on a first substrate; and a wavelength tunable reflection filter that is mounted on a second substrate, outputs single wavelength optical signals among the multi-wavelength optical signals using resonance of external cavity formed between a semiconductor laser diode and a Bragg-grating having a predetermined period, and tunes the wavelength of the output single wavelength optical signal by varying the refractive index of the Bragg-grating. The wavelength tunable Bragg-grating reflection filter and the semiconductor laser diode are mounted on separate substrates, and the optical coupling efficiency between the semiconductor laser diode and the waveguide type Bragg-grating reflection filter is increased using an active alignment method to increase the optical output power and enable a stable oscillation mode.

A clock reproducing apparatus includes a clock reproducing circuit having: a gated oscillator having an oscillating circuit of two routes; and a frequency control circuit for comparing a phase of an output of the gated oscillator with a phase of a reference clock, and supplying a phase control signal to the gated oscillator based on the comparison result so as to set a delay time, input data is input to a reset input terminal of the gated oscillator, and different route of the two routes of the oscillating circuit operates depending on a case where the input data is “H” and a case where the input data is “L”.

The present invention provides a spin torque oscillator that can realize stable oscillation and has high reliability. A laminated structure including a first magnetic layer 1 having a bcc crystal structure and having in-plane magnetic anisotropy and a second magnetic layer 2 having perpendicular magnetic anisotropy laminated on the first magnetic layer 1 and including a multilayer film of Co and Ni is used.

A method, apparatus, and system are provided for implementing a power-on spin-torque oscillator (STO) oscillation checker to monitor STO resistance to identify STO oscillation with microwave assisted magnetic recording (MAMR) hard disk drives (HDDs). A changing bias current is applied to the STO in the presence of constant write drive current. The STO bias current is changed to observe sudden changes in STO resistance monitored using a differentiator circuit to identify STO oscillation, used to ensure stable MAMR HDD write operation.

A narrow-band discharge excited laser device including a laser chamber having a laser gas sealed therein, a pair of electrodes provided within the laser chamber to face each other with a predetermined distance therebetween, a band-narrowing module having a magnifying prism and a grating and receiving laser light passing through a slit, and a cross-flow fan circulating the laser gas passing between the electrodes, in which a pulsed voltage is applied from a high-voltage power supply to the pair of electrodes to generate electric discharge between the electrodes, and the pair of electrodes have a width of 1 to 2 mm, a ratio between the electrode width and the inter-electrode distance (electrode with inter-electrode distance) being 0.25 to 0.125.

A circuit may comprise an amplifier powered by a first supply voltage, with a first input of the amplifier coupled to a stable reference voltage, and the output voltage of the amplifier provided as a designated supply voltage to an oscillator configured to produce a periodic signal having a specified frequency. The circuit may further include a control circuit coupled to a second input of the amplifier, to the output of the amplifier, and to ground, and configured to control the rate of change of the output voltage of the amplifier with respect to temperature. This rate of change may be specified according to a characterization of the oscillator over supply voltage and temperature, and may result in stabilizing the specified frequency across temperature. The periodic signal may therefore be unaffected by variations in the first supply voltage, and the amplitude of the periodic signal may be proportional to the stable reference voltage.

An optical semiconductor device and optical semiconductor integrated circuit are provided by combining, on a semiconductor substrate, materials having different refractive indices and different temperature dependence of the refractive indices. In particular, it becomes possible to control the temperature dependence of the oscillation wavelength with a propagating region having a material and / or structure whose temperature dependence of the refractive index is different from that of a gain region of the semiconductor laser. In addition, they can be configured to have a plurality of interfaces formed along the waveguide direction of the optical waveguide so that the light reflected off the first interface is weakened by the light reflected from the remaining interfaces. Also, they can be configured with the interfaces inclined to the propagating direction so that the waveguide loss due to the reflection and refraction between the optical waveguides whose refractive indices differ from each other can be reduced.

A wavelength converting device 1 has a substrate 5 made of an electro-optic material and converts a wavelength of a fundamental light to oscillate a converted light. A wavelength converting portion 7 is provided in the substrate 5 and has a cross sectional area of 0.0001 mm2 or larger and 0.01 mm2 or smaller. A pair of thinner portions 12A and 12B are provided in both sides of the wavelength converting portion, respectively, and thinner than the wavelength converting portion 7.

The present invention provides a spin torque oscillator that can realize stable oscillation and has high reliability. A laminated structure including a first magnetic layer 1 having a bcc crystal structure and having in-plane magnetic anisotropy and a second magnetic layer 2 having perpendicular magnetic anisotropy laminated on the first magnetic layer 1 and including a multilayer film of Co and Ni is used.

Disclosed are a near-field light source device as well as an optical head, an optical device, an exposure apparatus and a microscope device having such near-field light source device. As an example, the near-field light source device has a semiconductor laser having a ring-type optical resonator with a plurality of wave guides connected via mirror portions, a light blocking film formed in one of the mirror portions and having a small opening not greater than a wavelength size, and a diffraction grating formed on the light blocking film, wherein light oscillated from the semiconductor laser is diffracted by the diffraction grating, and the diffracted light is coupled to a rotation mode in the ring-type optical resonator.

A ripple converter includes a transistor for switching an input direct-current voltage, a choke coil and a smoothing capacitor for smoothing the switched direct-current voltage, a flywheel diode for causing a current to flow through the choke coil when the transistor is turned off, and a comparing unit for controlling the ON / OFF of the transistor according to ripple in an output voltage. In the ripple converter, a waveform converter is provided on a connecting path between an output terminal and a non-inverting input terminal of a comparator in the comparing unit. A result of converting the waveform of the output voltage is compared with a reference voltage, and a result of the comparison is fed back to the transistor.

A high-frequency power supply apparatus for supplying high-frequency power to a load the impedance of which greatly fluctuates is provided, wherein a stable high-frequency current is always maintained without having overcurrent or overvoltage generated in a drive circuit thereof. In the high-frequency power supply apparatus, a constant-current conversion circuit is connected between an LCR series resonant circuit and a half-bridge drive circuit, high-frequency current of the LCR series resonant circuit is controlled by the voltage of the half-bridge drive circuit, and a constant-current function is applied to impedance variation of the load. Due to the constant-current conversion circuit, the gate of a MOSFET of the half-bridge drive circuit is driven with a parallel capacitor using a transformer inserted in the LCR series resonant circuit, and the phases of the high-frequency current of the LCR series resonant circuit and the output of the half-bridge drive circuit are maintained to be constant.

The object of the present invention is to provide a compact and high output laser light coupler device. The solutions includes that each laser light beam La, Lb, Lc is emitted by a plurality of semiconductor laser 11A, 11B, 11C, passes a convergence lens 120, and is converged in the FAST axis. And light axis of each light beam La, Lb, Lc installs a convergence angle varying optical system 30 which is more upstream than the most upstream position Pa which is crossed position, looked in the FAST axis. The convergence angle varying optical system 30 makes convergence angle of the whole light beam which is made of each light beam La, Lb, Lc and which passes through a convergence-divergence optical system 120, become smaller convergence angle in the FAST axis, and makes the whole light beam emit into the core 41 of optical fiber 40.

The invention discloses a high-power all solid-state axisymmetric polarization laser for laser machining. The laser comprises an all solid-state laser generation device. The all solid-state laser generation device comprises a main oscillator for generating a laser beam and a power amplifier for amplifying the output power of the main oscillator, wherein the main oscillator comprises a completely reflecting mirror and an all solid-state single crystal pumping module, which are arranged along the same optical axis; and a polarized light focusing surface is formed between the completely reflecting mirror and the all solid-state single crystal pumping module. The laser also comprises a polarization element which is arranged at a joint of the optical axis between the completely reflecting mirror and the all solid-state single crystal pumping module and the polarized light focusing surface. By the laser, laser in an axisymmetric polarization state can be output, so that the efficiency and accuracy of the laser machining are improved.

An oscillator includes a resonator section structured such that a dielectric is interposed between first and second conductors and such that the first and second conductors are electrically connected to a resonant tunneling diode, a capacitor section structured such that the dielectric is interposed between the first and second conductors, a line section configured to electrically connect the resonator section and the capacitor section in parallel to each other, and a resistor section configured to electrically connect the first and second conductors to each other. A first position of the resonator section and a second position of the capacitor section are connected to each other by the line section so that the first position and the second position are substantially electrically equivalent to each other in a wavelength range larger than a wavelength of an electromagnetic wave that resonates in the resonator section.

A voltage-controlled oscillator that can achieve low phase noise while ensuring stable oscillation startup and stable oscillation maintenance even under low supply voltage conditions. The voltage-controlled oscillator includes an LC parallel resonant circuit, whose impedance varies with a control input voltage and a negative resistance circuit for introducing negative resistance into the LC parallel resonant circuit, wherein the negative resistance circuit includes at least: a first amplifier circuit, provided in parallel with the LC parallel resonant circuit and having a first pair of transistors cross-coupled via a capacitor, that achieves class-C amplifier operation by biasing the gate of each transistor in the first transistor pair with a first bias voltage; and a similarly configured second amplifier circuit that achieves class-C amplifier operation by biasing the gate of each transistor with a second bias voltage which is different from the first bias voltage.

A crystal oscillation circuit has a reduced circuit area and enables to stably oscillate at low consumed current. The crystal oscillation circuit includes an oscillating amplifier and a constant voltage generator. The oscillating amplifier excites a resonator composed of a resistor, a crystal oscillator and a capacitor. The constant voltage generator includes a one-stage differential circuit composed of a transistor and a capacitor for suppressing transient fluctuation of a constant voltage Vreg for generating the constant voltage Vreg served as a supply voltage for the oscillating amplifier. By generating the constant voltage Vreg through the one-stage differential circuit, the phase lag of the constant voltage Vreg reaches 90 degrees at most. This eliminates the necessity of a phase compensation capacitor, resulting in making the circuit area smaller and realizing the stable oscillation at low consumed current.