Northrop Grumman Systems Corporation

Northrop Grumman Guidance and Electronics Company, Inc.

Freedom Photonics LLC

Michael D Bulatowicz

Michael S Larsen

Robert C Griffith

Thad Gilbert Walker

Philip R Clark

Robert E Stewart

A Douglas Meyer

Henry C Abbink

Daryl K Sakaida

Eric A Imhof

Gordon Barbour Morrison

Bob Benjamin Buckley

Steven Ryan Jefferts

Dennis P Bevan

John Thomson Douglass

Douglas A Meyer

Thomas G Spence

Ming Li

Robert Buckley

Douglas Meyer

Robert Griffith

Daryl Sakaida

John Thomas Douglass

One example includes an atomic sensor system. The system includes an optical source configured to provide an optical beam and a plurality of sensor cell systems. Each of the sensor cell systems includes sensing media enclosed in a volume therein. The system also includes optics configured to provide the optical beam to each of the sensor cell systems to provide interaction of the optical beam with the vapor in each of the respective sensor cell systems. The optical beam exiting each of the sensor cell systems is a respective detection beam. The system further includes a detection system comprising at least one configured to receive the detection beam from each of the sensor cell systems and to determine a measurable parameter based on an optical characteristic associated with the detection beam from each of the sensor cell systems.

Atomic sensor system

One embodiment includes a vapor cell for an atomic physics-based sensor system. The vapor cell includes a cell wall formed from an approximately transparent material. The cell wall can enclose an alkali metal vapor and can include an inner surface and an outer surface. The vapor cell can also include at least one structural feature provided on at least one of the inner surface and the outer surface of the cell wall and extending along a portion of the respective at least one of the inner surface and the outer surface.

Vapor cell for atomic physics sensors

A heater system includes a current source configured to generate an input current and to receive a return current. The system also includes a heater configured to generate heat in response to the input current. The system further includes a plurality of current lead wires interconnecting the current source and the heater and being configured to provide the input current to the heater and to conduct the return current from the heater. Each of the plurality of current lead wires is arranged on a separate substrate layer such that each of the plurality of current lead wires are each spaced apart from each other. At least one of the input current and the return current is divided to be conducted on two or more of the plurality of current lead wires.

Heater system with magnetic field suppression

One example includes a magnetometer that includes a sensor cell comprising alkali metal vapor and a magnetic field generator system that generates predetermined AC magnetic fields through the sensor cell. The magnetometer also includes a laser system to provide optical pump and probe beams through the sensor cell in a pulsed manner to facilitate precession of the alkali metal vapor and to provide a detection beam corresponding to the optical probe beam exiting the sensor cell. The detection beam exhibits an optical property corresponding to a modified precession of the alkali metal vapor based on the predetermined AC magnetic fields and an external magnetic field. The magnetometer also includes a detection system to monitor the detection beam to detect the modified precession of the alkali metal vapor to calculate scalar and vector components of the external magnetic field based on the plurality of predetermined AC magnetic fields.

Synchronous light-pulse atomic magnetometer system

One example includes a magnetometer system that includes a sensor cell comprising alkali metal vapor and at least one measurement zone corresponding to a three-dimensional spatial region within the sensor cell. The system also includes a laser system configured to provide an optical pump beam through the sensor cell in a pulsed manner to facilitate precession of the alkali metal vapor in response to an external magnetic field and to provide an optical probe beam through the sensor cell in a pulsed manner based on a precession frequency of the alkali metal vapor. The system also includes a detection system configured to detect the precession of the alkali metal vapor in response to a detection beam corresponding to the optical probe beam exiting the sensor cell and to calculate an amplitude and direction of the external magnetic field based on the detected precession of the alkali metal vapor.

Pulsed-beam atomic magnetometer system

One embodiment of the invention includes a magnetometer system. The system includes a sensor cell comprising alkali metal particles and at least one nuclear spin isotope. The system also includes a probe laser to provide a probe beam through the sensor cell to generate a detection beam, and a magnetic field system to generate magnetic fields through the sensor cell. The system also includes a detection system to implement detection of an external magnetic field based on characteristics of the detection beam in response to precession of the at least one nuclear spin isotope based on the magnetic fields. The system further includes a calibration controller configured to calibrate the magnetometer system based on implementing predetermined changes to the magnetic fields and monitoring the detection beam in a feedback manner.

Calibration of a magnetometer system

One example includes a magnetometer system. The system includes a sensor cell comprising alkali metal vapor and a laser system configured to provide an optical pump beam through the sensor cell in a pulsed manner to facilitate precession of the alkali metal vapor in response to an external magnetic field and to provide an optical probe beam through the sensor cell in a pulsed manner based on a precession frequency of the alkali metal vapor. The system also includes a detection system configured to detect the precession of the alkali metal vapor in response to a detection beam corresponding to the optical probe beam exiting the sensor cell and to calculate an amplitude and direction of the external magnetic field based on the detected precession of the alkali metal vapor.

One embodiment includes a method for dynamic self-calibration of an accelerometer system. The method includes forcing a proof-mass associated with a sensor of the accelerometer system in a first direction to a first predetermined position and obtaining a first measurement associated with the sensor in the first predetermined position via at least one force/detection element of the sensor. The method also includes forcing the proof-mass to a second predetermined position and obtaining a second measurement associated with the sensor in the second predetermined position via the at least one force/detection element of the sensor. The method further includes calibrating the accelerometer system based on the first and second measurements.

Dynamic self-calibration of an accelerometer system

One example includes a method for fabricating a compound material. The method includes providing a first discrete material layer having a first thickness dimension. The first discrete material layer includes a first material having a first magnetic susceptibility. The method also includes depositing a second discrete material layer having a second thickness dimension over the first discrete material layer. The second discrete material layer can include a second material having a second magnetic susceptibility. The relative first and second thickness dimensions can be selected to provide a desired magnetic susceptibility of the compound material.

Customized magnetic susceptibility materials

One example embodiment includes an atomic sensor system. The system includes a vapor cell comprising an alkali metal vapor that precesses in response to a magnetic field. The system also includes a probe laser that generates an optical probe beam that is modulated about a center frequency and which is provided through the vapor cell. A photodetector assembly generates an intensity signal corresponding to a Faraday rotation associated with a detection beam that is associated with the optical probe beam exiting the vapor cell. The system further includes a detection system configured to demodulate the intensity signal at a frequency corresponding to a modulation frequency of the optical probe beam and to generate a feedback signal based on the demodulated intensity signal. The feedback signal is provided to the probe laser to substantially stabilize the center frequency of the optical probe beam based on the feedback signal.

Probe beam frequency stabilization in an atomic sensor system

One example includes a sensor system. A cell system includes a pump laser which generates a pump beam to polarize alkali metal vapor enclosed within a sensor cell. A detection system includes a probe laser to generate a probe beam. The detection system can calculate at least one measurable parameter based on characteristics of the probe beam passing through the sensor cell resulting from precession of the polarized alkali metal vapor in response to an applied magnetic field. A pump beam control system pulse-width modulates a frequency of the pump beam to provide a pulse-width modulated (PWM) pump beam, and controls a duty-cycle of the PWM pump beam based on the characteristics of the probe beam passing through the sensor cell in a feedback manner to control polarization uniformity of the alkali metal vapor and to mitigate the effects of AC Stark shift on the at least one measurable parameter.

Optical pump beam control in a sensor system

Embodiments of the invention include an accelerometer system. The system includes an accelerometer sensor comprising first and second electrode configurations and an inertial mass between the first and second electrode configurations. In one example, the accelerometer sensor being fabricated as symmetrically arranged about each of three orthogonal mid-planes. The system also includes an accelerometer controller configured to apply control signals to each of the first and second electrode configurations to provide respective forces to maintain the inertial mass at a null position between the first and second electrode configurations. The accelerometer controller can measure a first pickoff signal and a second pickoff signal associated with the respective first and second electrode configurations. The first and second pickoff signals can be indicative of a displacement of the inertial mass relative to the null position. The accelerometer controller can calculate an acceleration based on the first and second pickoff signals.

Accelerometer sensor system

One embodiment of the invention includes a magnetometer system. The system includes a sensor cell comprising alkali metal particles and a probe laser configured to provide a probe beam through the sensor cell. The system also includes a detection system configured to implement nuclear magnetic resonance (NMR) detection of a vector magnitude of an external magnetic field in a first of three orthogonal axes based on characteristics of the probe beam passing through the sensor cell and to implement electron paramagnetic resonance (EPR) detection of a vector magnitude of the external magnetic field in a second and a third of the three orthogonal axes based on the characteristics of the probe beam passing through the sensor cell. The system further includes a controller configured to calculate a scalar magnitude of the external magnetic field based on the magnitude of the external magnetic field in each of the three orthogonal axes.

Combined electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) magnetometer system

One embodiment includes an optical microphone system. The system includes a laser configured to emit an optical beam at a linear polarization and an optical cavity system comprising a membranous mirror that is configured to reflect the optical beam and to vibrate in response to an acoustic input signal. The optical cavity system includes at least one photodetector configured to receive at least a portion of the optical beam to generate a microphone signal that is indicative of the vibration of the membranous mirror resulting from the acoustic input signal based on the reflection of the optical beam. The system further includes an acoustic processor configured to process the microphone signal to calculate a frequency of the acoustic input signal.

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Canoga Park, CA, United States of America

Michael D Bulatowicz