4 results about "Off resonance" patented technology

In a general aspect, a quantum spectrum sensing system is presented. In some implementations, a system includes a laser system, a vapor cell sensor, an optical detector, and a signal processing system. The laser system includes a first laser that generates a first laser signal; a comb generator that produces a frequency comb signal based on the first laser signal; and a second laser generates a second laser signal. The vapor cell sensor includes a vapor and receives input optical signals based on the frequency comb signal and the second laser signal. The vapor cell sensor produces output optical signals based on interactions of the vapor with the input optical signals and electromagnetic radiation. The signal processing system processes the output optical signals to identifying signals in the electromagnetic radiation that are off resonance with a transition frequency between Rydberg states of the vapor.

A method for generating a magnetic resonance image of a subject using a magnetic resonance imaging (MRI) system includes receiving, using the MRI system, at least one parameter for a multiphoton parallel transmit excitation comprising a multiphoton excitation pulse configured to correct spatial inhomogeneities and performing, using the MRI system, a pulse sequence comprising the multiphoton parallel transmit excitation to acquire data from the subject. The multi photon excitation pulse of the multi photon parallel transmit excitation is performed using a radio frequency (RF) coil and a set of one or more shim coils of the MRI system. The method further includes generating, using a processor, an image of the subject using the acquired MR data. In some embodiments, the multiphoton excitation pulse includes an off-resonance RF excitation pulse performed using the RF coil and a plurality of low-frequency excitation pulses performed using the set of one or more shim coils. The plurality of low-frequency excitation pulses are performed simultaneously with the off-resonance RF excitation pulse.

The invention relates to a broadband measurement system and method based on Rydberg atoms, and belongs to the technical field of spectrum measurement. According to the system, the frequency of the local oscillation field applied to the atomic gas chamber is scanned, the frequency spectrums of the obtained intermediate frequency signals are continuously collected, and finally the broadband frequency spectrum information is obtained through splicing, so that the technical problems existing in the optical frequency comb mode locking process are solved, and cross-multi-frequency-range broadband electromagnetic frequency spectrum monitoring can be realized. According to the invention, the electromagnetic spectrum can be measured through the Rydberg probe. The microstrip line structure can generate a strong electric field on the surface and is small in size, so that the microstrip line structure is combined with the atomic probe to form the integrated atomic probe. Therefore, the measurement range of Rydberg atoms is expanded from a resonance point to a non-resonance point by using a heterodyne method, and the optimal sensitivity is-100dBm / Hz.

The application provides a double-resonance wireless power transmission system and method based on a special receiving end coil, wherein the receiving end of the double-resonance wireless power transmission system based on the special receiving end coil comprises a receiving end circuit, a receiving end non-resonance coil and a receiving end resonance coil; the receiving end non-resonance coil is formed with a main contact point, the main contact point is electrically connected to a first end of the receiving end circuit, and the receiving end non-resonance coil is further formed with a plurality of auxiliary contact points with different numbers of turns from the main contact point; the system further comprises a control module for acquiring the distance between the receiving end and the transmitting end; and a switching module for adjusting the number of turns of the receiving end non-resonance coil according to the distance in a certain rule, wherein a first end of the switching module is electrically connected to a second end of the receiving end circuit, a second end of the switching module is switchably electrically connected to an auxiliary contact point, and a control end of the switching module is electrically connected to the control module. The application realizes high-efficiency wireless power transmission with free movement at a single working frequency.