Small Rb atom frequency marking cavity bubble system

Abstract

The present invention discloses a miniaturized rubidium atomic frequency standard cavity-cell system, wherein, a microwave cavity cylinder is made from high magnetic permeability material; the microwave cavity cylinder is sleeved with a heating cylinder; a pump light incident port of the heating cylinder is also provided with a convex lens which gathers and transmits rays emitted by a rubidium spectral lamp into a microwave cavity; a C field coil is directly wound on a dielectric cylinder arranged between the microwave cavity cylinder and an absorption cell; a cusp on the tail part of a light-filtering cell is concentrated at the center of a circular plane at the end of the cell; a cusp on the tail part of the absorption cell is concentrated at the edge of a circular plane at the end of the cell; a photocell and a snap-off diode are fixed on the end face of the inner wall of a cavity end cover which can be movably fixed. The present invention has no machinery regulating rod inside the cavity, uses an intracavity frequency doubling mode, adopts a cylindrical TE111 mode and a dielectric filling method to get rid of the complex structure of a magnetic shield cylinder in the prior art, and reduces the volume of the cavity-cell system. As the pump light incident port of the heating cylinder is provided with the convex lens to increase the light intensity of pump light, the performance of the cavity-cell system is guaranteed. A mobile photoelectric component is adopted for cavity frequency fine adjustment, which is convenient for debugging and cannot cause field form distortion.

Description

technical field [0001] The invention relates to a rubidium atomic frequency standard that can be widely used in the fields of communication, positioning, measurement, earthquake reporting, national defense engineering and the like. More specifically, the invention relates to a cavity bubble system of the miniaturized rubidium atomic frequency standard. Background of the invention [0002] Atomic frequency standard (also known as atomic clock) is a device that provides standard frequency and time. Because of its small size, light weight, and low power consumption, it has become the most widely used atomic frequency standard. The basic principle of the rubidium atomic frequency standard is to use the transition spectrum of the rubidium atom to lock the voltage-controlled crystal oscillator, that is, the physical system of the rubidium atomic frequency standard outputs an optical detection signal with frequency discrimination characteristics, and obtains a DC error signal after ...

AI Technical Summary

Problems solved by technology

The former generally uses the so-called integrated filter technology (IFT), which combines the filter bubble and the absorption bubble into one bubble to reduce the volume of the bubble, but the shortcomings of this method are generally listed as performance indicators. at the expense of the reduction

The advantage of this microwave cavity is that it can realize the microwave cavity with the smallest volume. The disadvantage is that the cavity inside is square, the space utilization rate of atom filling is small, the contact surface is small when the commonly used cylindrical rubidium bubble is placed, and the mechanical stability is poor.

[0005] There is also a kind of patent in the United States [Jinquan Deng, Irvine, Calif.US.Pat.NO.6.133.800], [Ganghua Mei et al.US.Pat.NO.6.225.870.B1] and [IrvingLiberman et al. The non-standard cavities described in US.Pat.NO.5.670.914] have the advantage that the volume can be made relatively small, and the performance index can also be kept relatively high. The disadvantage is that the structure of the cavity is relatively complicated, and the cavity frequency Debugging is difficult, which is not conducive to mass production

None of the above-mentioned microwave cavities is equipped with step diodes, so a special extra-cavity frequency doubling device is required, which belongs to the extra-cavity frequency doubling method, which is not conducive to the reduction of the volume of the rubidium atomic frequency standard

Moreover, the C-field coils described in these patents are wound outside the microwave cavity. The disadvantage of this winding method is that the microwave cavity cannot be made of magnetic shield materials, so it is necessary to design a special magnetic shield tube outside the microwave cavity.

The second is that it sets the tip of the filter bubble and the tail of the absorbing bubble on the side of the cylinder, so that it is necessary to make grooves on the cylinder surface of the support cylinder and the cylindrical cavity to place the tip of the bubble body, which will damage the overall structure of the cavity. and it inserts the rubidium absorbing bubble into the slotted tube, opens a screw hole on the side of the cylindrical cavity, and installs a frequency fine-tuning screw in the hole. These methods may also cause distortion of the field shape in the cavity

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