Stability properties of an Rb CPT atomic clock with buffer-gas-free cells under dynamic excitation

Herein, a microfabricated millimeter-level vapor alkali cell with a high hermeticity is fabricated through a wet etching and single-chip anodic bonding process. The vapor cell, containing Rb and N2, was investigated in a coherent population trapping (CPT) setup for the application of a chip-scale atomic clock (CSAC). The contrast of CPT resonance is up to 1.1% within the only 1 mm length of light interacting with atom. The effects of some critical external parameters on the CPT resonance, such as laser intensity, cell temperature, and buffer gas pressure, are thoroughly studied and optimized. The improved microfabricated vapor cell also exhibited great potential for other chip-scale atomic devices.

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Fabrication and spectroscopy of Cs vapor cells with buffer gas for miniature atomic clock

EFTF-2010 24th European Frequency and Time Forum ◽

10.1109/eftf.2010.6533678 ◽

2010 ◽

Author(s):

D. Miletic ◽

C. Affolderbach ◽

E. Breschi ◽

C. Schori ◽

G. Mileti ◽

...

Keyword(s):

Atomic Clock ◽

Buffer Gas ◽

Vapor Cells

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Alkali Vapor MEMS Cells Technology toward High-Vacuum Self-Pumping MEMS Cell for Atomic Spectroscopy

Micromachines ◽

10.3390/mi9080405 ◽

2018 ◽

Vol 9 (8) ◽

pp. 405 ◽

Cited By ~ 4

Author(s):

Pawel Knapkiewicz

Keyword(s):

Cold Atoms ◽

High Vacuum ◽

Atomic Clock ◽

Atomic Spectroscopy ◽

Anodic Bonding ◽

Buffer Gas ◽

Optical Mems ◽

Preliminary Measurement ◽

Gas Atmosphere ◽

Measurement Results

The high-vacuum self-pumping MEMS cell for atomic spectroscopy presented here is the result of the technological achievements of the author and the research group in which he works. A high-temperature anodic bonding process in vacuum or buffer gas atmosphere and the influence of the process on the inner gas composition inside a MEMS structure were studied. A laser-induced alkali vapor introduction method from solid-state pill-like dispenser is presented as well. The technologies mentioned above are groundbreaking achievements that have allowed the building of the first European miniature atomic clock, and they are the basis for other solutions, including high-vacuum optical MEMS. Following description of the key technologies, high-vacuum self-pumping MEMS cell construction and preliminary measurement results are reported. This unique solution makes it possible to achieve a 10−6 Torr vacuum level inside the cell in the presence of saturated rubidium vapor, paving the way to building a new class of optical reference cells for atomic spectroscopy. Because the level of vacuum is high enough, experiments with cold atoms are potentially feasible.

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Optimization of Buffer Gas Compositions in Atomic Vapor Cell for Coherent Population Trapping Atomic Clock

Laser & Optoelectronics Progress ◽

10.3788/lop56.120201 ◽

2019 ◽

Vol 56 (12) ◽

pp. 120201

Author(s):

李云超 Yunchao Li ◽

胡旭文 Xuwen Hu ◽

张璐 Lu Zhang ◽

刘召军 Zhaojun Liu ◽

张开放 Kaifang Zhang ◽

...

Keyword(s):

Atomic Clock ◽

Coherent Population Trapping ◽

Buffer Gas ◽

Atomic Vapor ◽

Vapor Cell ◽

Population Trapping

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Microfabrication of Alkali Vapor MEMS Cells for chip-scale atomic clock

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012188 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012188

Author(s):

A Kazakin ◽

R Kleimanov ◽

I Komarevtsev ◽

A Kondrateva ◽

Y Enns ◽

...

Keyword(s):

Chemical Etching ◽

Optical Cavity ◽

Atomic Clock ◽

Single Step ◽

Coherent Population Trapping ◽

Anodic Bonding ◽

Buffer Gas ◽

Wet Chemical ◽

Wet Chemical Etching ◽

Population Trapping

Abstract The technology of MEMS atomic cells containing rubidium or caesium vapors in an atmosphere of neon buffer gas has been developed. Two-chamber silicon cells containing an optical cavity, shallow filtration channels and a technical container for a solid-state alkali source have been implemented in a single-step process of anisotropic wet chemical etching. To prevent significant undercutting of the filtration channels during etching of the through silicon cavities, the shapes of the compensating elements at the convex corners of the silicon nitride mask have been calculated and the composition of the silicon etchant has been experimentally found. The sealing of the cells has been carried out by silicon-glass anodic bonding at a temperature of 250 °C. For this purpose the LK5 glass which has an increased ionic conductivity in comparison with the conventional glass Borofloat 33 was used. The best microfabricated cells allowed us to obtain estimates of the relative instability of the coherent population trapping resonance frequency at the level of 5 · 10-11 at 1 s.

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vitreal cells and specialized phagocytes in the chick embryo retina: A TEM and SEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159205 ◽

1990 ◽

Vol 48 (3) ◽

pp. 330-331

Author(s):

M.A. Cuadros ◽

M.J. Martinez-Guerrero ◽

A. Rios

Keyword(s):

Cell Death ◽

Plasma Membrane ◽

Acid Phosphatase ◽

Chick Embryo ◽

Basement Membrane ◽

Sem Images ◽

Intimate Contact ◽

Cellular Processes ◽

Sem Study ◽

Free Cells

In the chick embryo retina (days 3-4 of incubation), coinciding with an increase in cell death, specialized phagocytes characterized by intense acid phosphatase activity have been described. In these preparations, all free cells in the vitreal humor (vitreal cells) were strongly labeled. Conventional TEM and SEM techniques were used to characterize them and attempt to determine their relationship with retinal phagocytes.Two types of vitreal cells were distinguished. The first are located at some distance from the basement membrane of the neuroepithelium, and are rounded, with numerous vacuoles and thin cytoplasmic prolongations. Images of exo- and or endocytosis were frequent; the cells showed a well-developed Golgi apparatus (Fig. 1) In SEM images, the cells was covered with short cellular processes (Fig. 3). Cells lying parallel to or alongside the basement membrane are elongated. The plasma membrane is frequently in intimate contact with the basement membrane. These cells have generally a large cytoplasmic expansion (Fig. 5).

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Partial Activation of Purified Prothrombin: Derivation of Autoprothrombin I with Use of Autoprothrombin C

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655472 ◽

1962 ◽

Vol 07 (02) ◽

pp. 239-248 ◽

Cited By ~ 1

Author(s):

Walter H Seegers ◽

Edmond R Cole ◽

Ewa Marciniak

Keyword(s):

Calcium Ions ◽

Platelet Factor ◽

Stability Properties ◽

Partial Activation ◽

Autoprothrombin C

SummaryActivation of purified prothrombin with autoprothrombin C in the absence of calcium ions produces autoprothrombin I activity. The solubility, and stability properties of this autoprothrombin I are different from those of autoprothrombin I when obtained by activating prothrombin with calcium ions, platelet factor 3, and Ac-globulin.

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