Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
In this paper, we get through some work to solve a detailed problem of the cesium active optical clock. With 459 nm laser pumping, the exact hyperfine energy levels between which the stimulated emission of Cs active optical clock takes place are studied.
We realize a Faraday anomalous dispersion optical filter (FADOF) operating on the 88Sr (5s2)1S0-(5s5p)1P1 transition, utilizing a strontium hollow cathode lamp (HCL). At the magnetic field strength of 1460 G and the HCL discharge current of 22 mA, a single transmission peak with a maximum transmission of 28.8% is obtained. The dependence of transmission on magnetic field and HCL discharge current...
The concept of active optical clock was proposed ten years ago. In this paper, after a simple review, we will mainly present the most recent experimental progresses of active optical frequency standards in Peking University, including 4-level Cesium active optical frequency standards and active Faraday optical frequency standards.
In this paper, we present a laser scheme without cavity in a 10 cm cesium cell as a potential active optical frequency standard. Since no cavity is applied, the stimulated light is emitted from the atoms directly and the center frequency of output laser light is solely determined by atoms without cavity pulling. The threshold characteristic of the emitted light is measured. This scheme can be used...
Candela is one of the seven base units in the SI. The units of time and length have been defined in quantum method and the others of the base units have the potential to be redefined in quantum method or on fundamental constants, except candela. With the accuracy of measurement and application increasing, the requirement of a more accurate definition of candela is becoming urgent. In this paper, we...
An active optical clock can provide laser light source with potential much narrower linewidth than that of conventional cavity stabilized laser for optical clocks since many cavity noises, including the Brownian thermal noise, can be reduced by orders of magnitude. In this report, a scheme of active optical clock based on Sr atomic beam is proposed. The experimental work of population inversion has...
We realize the lasing of cesium active optical clock with 459 nm laser pumping, which operates deep in the optical bad-cavity regime. The ratio between cavity bandwidth and gain bandwidth is 55.08 theoretically. With 459 nm laser pumping, the population inversion occurs between the cesium 7S1/2 state and 6P3/2 state, and the stimulated radiation between the two states is realized. The 1469.9 nm output...
In order to develop small optical clock for various transportable applications with better stability and accuracy than that of commercial small Cs clock and H-maser clock, our group has proposed a small Ca atomic beam clock scheme with electron-shelving detection. Its potential stability was experimentally demonstrated recently. Here, we first demonstrated the dispersive detection of 657 nm transition...
We are setting up an experiment to investigate an active optical clock scheme in four-level configuration with Cesium atoms. The 1469 nm Cesium active optical clock output in a bad cavity laser regime is generated and the wavelength is measured to be 1469.500 nm by using spectrometer. The 1469 nm lasing threshold and output power is measured when changing 455 nm pumping laser power and frequency....
We propose an active optical clock scheme in four-level configuration with cesium atoms. The population inversion has been established experimentally between 7S1/2 state and 6P3/2 state in a thermal cesium cell with a 455.5 nm pumping laser. It can be used to generate active optical clock laser output in a bad cavity laser regime at the wavelength of 1469 nm.
An excited-state Faraday anomalous dispersion optical filter (FADOF) has been demonstrated, which utilizes a rubidium electrodeless-discharge-vapor-lamp rather than an external pump laser. When the lamp is turned off, the lamp-based filter can be treated as a ground-state FADOF. The compact lamp based FADOF holds promise for realing a frequency-fixed diode laser systems (such as a 1529 nm laser for...
This paper presents a 12-bit 500MS/s DAC with a novel current switch driver. Compared to traditional low cross-point driver, the driver can generate a lower cross-point that is immune to process and temperature variation. Compared to traditional clock feedthrough compensation scheme, the driver compensates the clock feedthrough at the outputs without introducing additional frequency component across...
Biobased production of fuels from renewable resources has gained high research and development priority due to issues of national security regarding US fossil fuel consumption and concerns about the environmental impacts of burgeoning greenhouse gases. Currently, most ethanol production in the US uses corn as the feedstock. However, corn production significantly contributes to water quality degradation,...
Biobased fuels from renewable resources has gained high research and development priority due to national security and environmental concerns. To ensure resilience and sustainability of the nation's agricultural and fuel sectors, it is essential to evaluate the effect of recent and foreseeable environmental effects from agricultural cultivation. This study examines the environmental impacts of fertilizers...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.