banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
A low-power, high-sensitivity micromachined optical magnetometer
Rent this article for
View: Figures


Image of FIG. 1.
FIG. 1.

(a) Photograph of the microfabricated, fiber-optically coupled magnetometer sensor head. The volume of a cuboid that would entirely enclose the assembled sensor head is 0.36 cm3. The probe light fiber is held in structure A, the cell in structure B, and the photodetector and heating light fiber in structure C. (b) Schematic of the sensor head assembly, showing the vapor cell illuminated from above by the probe light (solid red line) and from below by the heating light (dashed green line). PM: Polarization-maintaining optical fiber; MM: multi-mode optical fiber; L1, L2: lenses; P: reflecting prisms; QWP: quarter-wave plate; VAC: evacuated enclosure; S: polyimide web; F: optical filter; C: vapor cell; D: dichroic mirror; PD: photodiode.

Image of FIG. 2.
FIG. 2.

Noise equivalent magnetic field measured in the sensor for the in-phase (blue solid line) and out-of-phase (red dashed line) lock-in output signals. The solid straight line shows a sensitivity of 16 fT/√Hz. The inset shows a typical magnetic resonance signal as the fractional optical power transmitted through the vapor cell as a function of magnetic field.

Image of FIG. 3.
FIG. 3.

Comparison of the equivalent magnetic noise measured with our optical magnetometers (Trace C, blue) with that of a typical commercial SQUID magnetometer (Trace D, red). Also shown is the average of the spectra of 102 SQUID magnetometers in a helmet-shaped sensory array positioned 18 mm above the scalp, measuring the magnetic field produced by a typical human brain (Trace B, green). The red hatched region (A) shows the expected enhancement of this brain spectrum for a sensor placed 2.5 mm above the scalp (see Ref. 24 for additional details). The SQUID (Trace D, red) and brain field (Trace B, green) data were originally presented in Ref.23.


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: A low-power, high-sensitivity micromachined optical magnetometer