173 results about "Atomic frequency standard" patented technology

The invention discloses a method and a device for implementing a Ramsey-CPT atomic clock by microwave On-Off modulation VCSEL. The method comprises the following steps of: A, coupling direct current and microwave to a laser tube, scanning the direct current to obtain a plurality of absorption peaks and locking the direct current; B, switching on and off the microwave to realize equivalent laser pulse, and scanning the microwave to obtain Ramsey-CPT stripes; and C, locking the microwave to obtain stable frequency output. The device is characterized in that: a current source is connected with a Bias-Tee, a microwave source is connected with the Bias-Tee through a microwave switch, the Bias-Tee is connected to a laser generating device, the output laser passes through a physical system and then enters a laser detection device, and control equipment is connected with the current source, the microwave source, the microwave switch and the laser detection device respectively. The method and the device realize laser-atom periodic interaction through microwave On-Off, have a more predominant frequency discrimination curve compared with the traditional CPT scheme, and implements the atomic block with higher stability. Compared with the Ramsey-CPT atomic clock implemented by using the AOM with larger volume and higher power consumption, the device has a simple structure, adopts a unique method, is easy for microminiaturization, and overcomes the key technology of the chip Ramsey-CPT atomic clock.

An optically-excited atomic frequency standard that subjects alkali metal atoms (111) to circularly-polarized optical radiation. The atomic frequency standard is improved by the use of a circular polarizer (202) to control the intensity of the circularly-polarized optical radiation. The circular polarizer includes a linear polarizer (203) and a quarter-wave retarder (205), with the light to be circularly polarized passing first through the linear polarizer (203) and then through the quarter-wave retarder (205). In the atomic frequency standard, the optical radiation (105) to which the circular polarizer (202) is applied is itself linearly polarized, and the intensity of the circularly polarized light produced by the circular polarizer (202) is controlled by rotating (303) the circular polarizer. The degree of rotation determines how much of the linearly-polarized optical radiation passes through the linear polarizer, and thus how much circularly-polarized light is produced.

In an apparatus using optically excited atomic media, such as an atomic frequency standard, a source providing a controlled emission of light for exciting the D1 and / or D2 resonance lines of an alkali gas, such as rubidium or cesium, is controlled by an output generated by digital electronics from the light intensity signal of a light sensor for light transmitted by the alkali gas, an output for representing ambient temperature, and a light intensity-ambient temperature algorithm to substantially eliminate changes in light intensity due to light source aging for the purpose of reducing changes in temperature sensitivity of the apparatus as a function of time and the light-shift contribution to the frequency aging of the standard.