National Technology & Engineering Solutions of Sandia, LLC

Sandia Corporation

Quspin, Inc.

Peter Schwindt

Grant Biedermann

Yuan-Yu Jau

Jongmin Lee

Hayden James Evans McGuinness

Murat Okandan

David R Wheeler

Roy H Olsson

Darwin K Serkland

Charles A Walker

Matthew G Blain

Vishal Shah

David Bossert

Cort Nolan Johnson

Daniel L Stick

Aaron M Ison

Daniel Paul Gillund

Akash Rakholia

Cort N Johnson

Kaleb Lee Campbell

Amir Borna

Tony Ray Carter

Joonas Aleksanteri Iivanainen

Shanalyn A Kemme

Kyle H Fuerschbach

A compact grating-mirror magneto-optical trap (GMOT) cold atom inertial sensor head is disclosed. To make the sensor head compatible with the high vibration levels encountered in dynamic environments, the number of optical ports in the vacuum chamber is minimized and various components, including fixed optical components and a reflective grating chip, are hard mounted within the vacuum chamber. The use of the reflective grating chip reduces the number of optical ports required for cooling beams from six to one. The number of optical ports is further reduced by time multiplexing multiple beams passing through a given optical port.

Compact grating magneto-optical trap sensor head for inertial navigation in dynamic environments

Various optical systems for use in a light pulse atomic interferometer (LPAI)-based one-, two-, or three-axis accelerometer or gyroscope are disclosed. As an LPAI accelerometer or gyroscope may employ many different laser beams to implement the LPAI functionality, ways of combining these different laser beams to thereby simplify the optical systems are desired. The cooling laser beam portion of the optical system may be simplified using one or more reflective grating chips. The Raman laser beam optics may be simplified using combiners and separators. For LPAI systems sensing along three axes, various optical switching schemes may be employed, including ones that generate variable data-rates with a primary sensing axis having a higher data-rate than the secondary sensing axes. Further, by combining various laser beams in a time-multiplexed manner, the number of optical fiber tethers to a sensor head may be reduced.

Compact atom interferometry inertial navigation sensors with tailored diffractive optics

An atomic magnetometer, and a method for using same is disclosed. The method for measuring an ambient magnetic field uses an atomic magnetometer that has a probe light beam with a probe axis that probes a polarization vector of an atomic population confined within a vapor cell. The method employs one or more measurement cycles. In each measurement cycle, the polarization vector is prepared in an initial state via an optical pumping pulse. The vapor cell is then subjected to the ambient magnetic field, which results in rotation of the polarization vector by Larmor precession. Within the measurement cycle, at a point in time after the polarization vector has been prepared in the initial state, the ambient magnetic field rotates the direction of the polarization vector, and at least one measurement is made of a projection of the Larmor-rotated polarization vector onto the probe axis during or after application of a magnetic waveform.

Vector measurements using a pulsed, optically pumped atomic magnetometer

A method is provided for sensing a magnetic field in a magnetic gradiometer of the kind in which pump light and light constituting an optical carrier traverse first and second atomic vapor cells that contain host atoms and that are separated from each other by a known distance. According to such method, the host atoms are prepared in a coherent superposition of two quantum states that differ in energy by an amount that is sensitive to an ambient magnetic field. Modulation of the optical carrier in the respective cells gives rise to sidebands that interfere to generate a beat frequency indicative of the magnetic field gradient. The host atoms are prepared at least in a mode that allows measurement of ambient magnetic field components perpendicular to the axis of the pump light. In such mode, the host atoms are spin-polarized by pump light while subjected to a controlled magnetic field directed parallel to the pump beam, and then the controlled magnetic field is adiabatically extinguished.

Optically pumped gradient magnetometer

An atomic magnetometer includes an atomic vapor cell, an optical system conformed to transmit pump radiation and probe radiation through the vapor cell, and an optical detection system arranged to receive and detect probe radiation after it exits the vapor cell. Improvements in the separation of spatial channels are achieved by using a a diffractive optical element arranged to divide at least the pump radiation into a plurality of separate diffracted beams that traverse the vapor cell.

Atomic magnetometer with multiple spatial channels

An atomic interferometric device useful, e.g., for measuring acceleration or rotation is provided. The device comprises at least one vapor cell containing a Raman-active chemical species, an optical system, and at least one detector. The optical system is conformed to implement a Raman pulse interferometer in which Raman transitions are stimulated in a warm vapor of the Raman-active chemical species. The detector is conformed to detect changes in the populations of different internal states of atoms that have been irradiated by the optical system.

Light-pulse atom interferometric device

An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

Atomic magnetometer

A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

Microfabricated ion frequency standard

An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

Tuned optical cavity magnetometer

Growing community of inventors

Albuquerque, NM, United States of America

Peter Schwindt