60 results about "Short term stability" patented technology

A cold atom all-optical state selection device comprises vacuum flange, an optical state-selecting region, a magneto-optical trap, and a cavity base connected in sequence from top to bottom; when thecold atomic fountain clock starts to work, based on the magneto-optical trap cooling, trapping to get cold atomic groups and simultaneously preparing the clock state during the throwing of the cold atomic groups. The invention not only greatly increases the number density of the clock state atoms, but also shortens the height of the whole clock, thereby greatly shortening the dead time of the intermittent clock, thereby achieving the purpose of shortening the cycle and improving the short-term stability of the cold atomic clock. The device has a simple structure and is easy to implement, and can be used as a core device of a laser cold atomic clock.

The invention discloses a method and a device for optimizing short-term stability parameters of an atomic frequency standard, which belong to the field of the atomic frequency standards. The method comprises the steps that a plurality of working parameter points are set; each working parameter point includes a plurality of experiment points which correspond to different parameters to be optimized, each parameter to be optimized corresponds to the plurality of experiment points, and the quantities of the corresponding experiment points are the same, the experiment points corresponding to the same parameter to be optimized are evenly distributed in a value area including two end points of the parameter to be optimized, at most one same experiment point exists in every two working parameter points, and the frequency of each experiment point in all the working parameter points is the same; each parameter to be optimized includes modulation depth, modulation frequency and microwave power; according to each working parameter point, the modulation depth, the modulation frequency and the microwave power are respectively regulated; and frequency discrimination gradient of the atomic frequency standard corresponding to each working parameter point is calculated, and the optimal working parameter point is selected. The method and the device improve the short-term stability of the atomic frequency standard.

A system for optimizing short-term stability of a clock from a clock source synchronized with a first reference clock source with long-term stability transmits numbers of clocks of a first reference clock from the first reference clock source (21, 22, 23, 24) to the clock source (8) between an initialization time and a plurality of times in each case in a data-packet-oriented network (9). The clock from the clock source (8) is adjusted by correcting a difference between numbers of clocks of the first reference clock which are received in the clock source (8) and numbers of clocks of the first reference clock between the initialization time and the respective times at which the numbers of clocks of the first reference clock are received. In addition, numbers of clocks of a second reference clock for the data packet are transmitted to the clock source (8) at individual times with the number of clocks from at least one second freewheeling reference clock source (111, 112). The maximum difference between the first reference clock and the second reference clock from the clock source (8) is known. The difference between the clock from the clock source (8) and each second reference clock is limited to a first adjustable threshold value.

The invention discloses a constant temperature crystal oscillator high-precision frequency control device and a control method thereof. The device comprises a control computer, an MCU single chip, a high-precision digital-analogue converter and a constant temperature crystal oscillator; the control computer is used for converting an appointed voltage value into a serial instruction to output to the MCU single chip; the MCU single chip is used for converting the serial instruction into a binary instruction in tri-channel 24bit so as to transmit to the high-precision digital-analogue converter as an analogue time sequence; the high-precision digital-analogue converter is used for producing appointed analogue voltage amount to control the frequency of the constant temperature crystal oscillator. Electric control voltage resolution of the constant temperature crystal oscillator is improved to achieve 7.82muV; a constant control voltage is given to the constant temperature crystal oscillator, the stability of the output frequency achieves the nominal extremity which is 7.8*10<-14>(@average time: 8s); only one serial port of the computer is occupied and a data acquiring card channel cannot be occupied, thus the control process to the constant temperature crystal oscillator is simplified; the short-term stability of the constant temperature crystal oscillator after being locked by an atom fountain device achieves 2.8*10<-13>tau<-1/2>.

The invention provides a hydrogen and cesium time scale fusion method based on Vondik-Cepek filtering. Firstly, using an exponential filtering method for respectively generating a clock group time scale for a hydrogen clock group and a cesium clock group; and then selecting a Vondik-Cepek combined filtering key parameter according to a least square principle, and further performing performance enhancement on the cesium clock group time scale through differential information of the hydrogen clock group time scale time sequence, thereby obtaining a hydrogen-cesium fusion time scale. According tothe method, the noise is effectively suppressed, meanwhile, the characteristics of hydrogen and cesium atomic clocks can be considered, fusion is carried out on the clock group scale level, and the time scale with good long-term and short-term stability is generated.

The invention discloses an end-coupling nano optical waveguide type dual-optical-path chip-scale atomic clock comprising a laser device. An emergent light beam of the laser device enters a Y-waveguide beam splitter through coupling of the end-coupling input end, wherein one light beam is outputted after passing through a phase modulation unit while the other light beam is outputted after adjust compensation, and the two light beams are outputted after passing through a vertical coupling grating II and a vertical coupling grating III respectively and sequentially pass through a polaroid, attenuation slices, a wave plate, collimation and focusing prior to entering an air chamber. After being emergent, the two light beams are converted into electrical signals through a detection unit, the electrical signals are inputted into an integrated circuit chip through a subtracter, and the integrated circuit chip is used for regulating and controlling the laser device and the phase modulation unit. The end-coupling nano optical waveguide type dual-optical-path chip-scale atomic clock has the advantages that the effect of optical power fluctuation and frequency fluctuation noise can be greatly weakened and the signal-to-noise ratio of the CPT atomic clock can be effectively improved through dual-optical-path common-mode rejection, so that short-term stability of the chip-scale atomic clock can be greatly enhanced.