High Resolution Microwave B-Field Imaging Using a Micrometer-Sized Diamond Sensor^*

Abstract

We propose a diamond-based micron-scale sensor and perform high-resolution B-field imaging of the near-field distribution of coplanar waveguides. The sensor consists of diamond crystals attached to the tip of a tapered fiber with a physical size on the order of submicron. The amplitude of the B-field component B is obtained by measuring the Rabi oscillation frequency. The result of Rabi sequence is fitted with a decayed sinusoidal. We apply the modulation-locking technique that demonstrates the vector-resolved field mapping of the micromachine coplanar waveguide structure (CPW). B-field line scan was performed on the CPW with a scan step size of 1.25 μm. To demonstrate vector resolved rf field sensing, a full field line scan acts (was performed) along four NV axes at a height of 50 μm above the device surface. The simulations are compared with the experimental results by vector-resolved measurement. This technique allows the measurement of weak microwave signals with a minimum resolvable modulation depth of 20 ppm. The sensor will have great interest in micron-scale resolved microwave B-field measurements, such as electromagnetic compatibility testing of microwave integrated circuits and characterization of integrated microwave components.

Design of compact integrated diamond nitrogen–vacancy center quantum probe

“…As a superior magnetic sensing platform, the negatively charged nitrogen-vacancy (NV) center in diamond has attracted extensive attention, primarily owing to its nano-scale spatial resolution and high magnetic sensitivity. [1][2][3] Using the optically detected magnetic resonance (ODMR) technology, the electron spin can be initialized, manipulated, and measured by using optical excitation and microwave, [4,5] which lays a foundation for quantum information processing and precision measurement. [6] In conventional experiments, optical components such as objectives, lenses, and dichroic mirrors are employed to guide light for initialization and detection.…”

Surface H‐field mapping of a microwave limiter chip based on quantum diamond probe

“…The physical size is too large to be applicable for chip characterization. 10,11 The diamond probe in this work is quantum calibrated, nonintrusive, and frequency tunable from DC to millimeterwave frequencies and above. More specifically, we have compared our equipment with that of the German company Langer, the important metrics shown in Table 1.…”

“…Moreover, commercial probes are primarily available only in the sub‐6 GHz bands, with quite a few selections up to 20 GHz. The physical size is too large to be applicable for chip characterization 10,11 . The diamond probe in this work is quantum calibrated, nonintrusive, and frequency tunable from DC to millimeterwave frequencies and above.…”