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Transcript of Active optical gyroscope with controllable evmik/talks/2016.LPHYS.gyro.pdf Active optical gyroscope

  • Active optical gyroscope with controllable dispersion.

    Eugeniy E. Mikhailov, Owen Wolfe, Irina Novikova1, Simon Rochester, Dmitry Budker2,

    1

    2

    LPHYS, 14 July 2016

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 1 / 17

  • Sagnac effect and cavity response

    beam splitter

    input

    detector

    output

    E cw

    E ccw

    ∆p = ±ΩRt = ±2AΩ c

    ∆f = f0 ∆p p

    1 ng

    = ∆fempty 1 ng

    Group index

    ng(f ) = n + f0 ∂n ∂f

    vg = c/ng

    Cavity response enhanced if ng < 1 i.e. under the fast light condition Shahriar et al., PRA 75, 053807 (2007)

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 2 / 17

  • Sagnac effect and cavity response

    beam splitter

    input

    detector

    output

    E cw

    E ccw

    ∆p = ±ΩRt = ±2AΩ c

    ∆f = f0 ∆p p

    1 ng

    = ∆fempty 1 ng

    Group index

    ng(f ) = n + f0 ∂n ∂f

    vg = c/ng

    Cavity response enhanced if ng < 1 i.e. under the fast light condition Shahriar et al., PRA 75, 053807 (2007)

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 2 / 17

  • EIT - slow light

    | 2 〉

    | 1 〉

    | 3 〉

    δ

    ∆ HFS

    | 4 〉

    Ω 1Ω 2

    ∆ 1

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 3 / 17

  • N-bar with four-wave mixing - fast and with gain

    | 2 〉

    | 1 〉

    | 3 〉

    δ

    ∆ HFS

    | 4 〉

    Ω 1Ω 2

    ∆ 1 Ω 3

    ∆ 3

    γ 42

    γ 41

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 5 / 17

  • N-bar with Doppler averaging

    Refractive index Absorption

    Stationary atoms

    Room temperature Doppler averaged

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 6 / 17

  • N-bar levels and fields diagram

    Artificial atom 87Rb atom

    F=2

    F=1

    F’=2

    F’=1

    m=1m=0m=-1m=-2 m=2

    F’=2

    F’=1

    F’=3

    F’=0

    5P

    5P

    5S

    3/2

    1/2

    1/2

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 7 / 17

  • The first gyro setup and its performance

    Finesse = 20

    → Pulling 1/200

    D1 tuned around Fg = 1→ Fe = 1,2

    E. Mikhailov, et al. Optical Engineering, Issue 10, 53, 102709, (2014)

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 8 / 17

  • The first gyro setup and its performance

    P.F . = ∆fdispersive

    ∆fempty =

    1 ng

    ∆fempty = f0 ∆p p

    Finesse = 20 → Pulling 1/200

    E. Mikhailov, et al. Optical Engineering, Issue 10, 53, 102709, (2014) Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 8 / 17

  • Gyro lasing: theory vs. experiment

    |2〉

    |1〉

    |3〉

    δ

    ∆HFS

    |4〉

    Ω 1Ω 2

    δ1 Ω 3

    δ 3 Ω 4

    δ 2 P

    δ 4

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 9 / 17

  • Gyro pulling and amplitude vs. gyro cavity detuning

    Cavity detuning span 150 MHz. Pulling ×100

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 10 / 17

  • Pulling factor with increased cavity finesse (20→ 70)

    |2〉

    |1〉

    |3〉

    δ

    ∆HFS

    |4〉

    Ω 1Ω 2

    δ1 Ω 3

    δ 3 Ω 4

    δ 2 P

    δ 4

    λ/2

    FIBER

    LENS

    PBS LENS

    D1 LASER

    Rb Cell

    MAGNETIC

    SHIELDING

    Rb87

    PBS

    D2 LASER

    CAMERA

    FIBER BEAM SPLITTER

    SCOPE

    PD

    Spectrum Analyzer

    FAST PD

    P.F . = ∆fdispersive

    ∆fempty

    = 1 ng

    ∆fempty = f0 ∆p p

    −600 −400 −200 0 200 −0.05

    0

    0.05

    0.1

    0.15

    0.2

    0.25

    0.3

    20150803: Pulling factor vs. D 2 laser detuning

    D 2 laser detuning from F

    g =2 −> F

    e =3, MHz

    P u

    lli n

    g f

    a c to

    r

    −600 −400 −200 0 200 0

    0.05

    0.1

    0.15

    0.2

    20150803: Pulling factor averaged vs. D 2 laser detuning

    D 2 laser detuning from F

    g =2 −> F

    e =3, MHz

    P u

    lli n

    g f

    a c to

    r

    −600 −400 −200 0 200 −100

    −90

    −80

    −70

    −60

    −50

    20150803: Beat−note span vs. D 2 laser detuning

    D 2 laser detuning from F

    g =2 −> F

    e =3, MHz

    F re

    q u

    e n

    c y ,

    M H

    z

    −600 −400 −200 0 200 −90

    −85

    −80

    −75

    −70

    20150803: Beat−note amplitude vs. D 2 laser detuning

    D 2 laser detuning from F

    g =2 −> F

    e =3, MHz

    B e

    a t−

    n o

    te a

    m p

    lit u

    d e

    , d

    B m

    0 1 2 3 4 −0.1

    0

    0.1

    0.2

    0.3

    0.4

    20150804: Pulling factor vs. D 2 power

    D 2 power, mW

    P u

    lli n

    g f

    a c to

    r

    0 1 2 3 4 −0.1

    0

    0.1

    0.2

    0.3

    0.4

    20150804: Pulling factor averaged vs. D 2 power

    D 2 power, mW

    P u

    lli n

    g f

    a c to

    r

    0 1 2 3 4 −86

    −84

    −82

    −80

    −78

    −76

    −74

    20150804: Beat−note span vs. D 2 power

    D 2 power, mW

    F re

    q u

    e n

    c y ,

    M H

    z

    0 1 2 3 4 −90

    −85

    −80

    −75

    −70

    20150804: Beat−note amplitude vs. D 2 power

    D 2 power, mW

    B e

    a t−

    n o

    te a

    m p

    lit u

    d e

    , d

    B m

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 11 / 17

  • Dependence on total pumps power

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 12 / 17

  • Dependence on 87Rb vapor density

    Low pumps power

    1.5 2 2.5 3 3.5

    x 10 12

    0.06

    0.08

    0.1

    0.12

    0.14

    0.16

    Vapor Density, (N particles

    cm −3

    )

    P u

    lli n

    g f

    a c to

    r

    20151002: Pulling factor vs. Vapor Density

    1.5 2 2.5 3 3.5

    x 10 12

    0.06

    0.08

    0.1

    0.12

    0.14

    0.16

    Density, 1/cm 3

    P u

    lli n

    g f

    a c to

    r

    20151002: Pulling factor averaged vs. Vapor Density

    1.5 2 2.5 3 3.5

    x 10 12

    −440

    −420

    −400

    −380

    −360

    −340

    Vapor Density, (N particles

    cm −3

    )

    F re

    q u

    e n

    c y ,

    M H

    z

    20151002: Beat−note span vs. Vapor Density

    1.5 2 2.5 3 3.5

    x 10 12

    −86

    −84

    −82

    −80

    −78

    −76

    Vapor Density, (N particles

    cm −3

    ) B

    e a

    t− n

    o te

    a m

    p lit

    u d

    e ,

    d B

    m

    20151002: Beat−note amplitude vs. Vapor DensityHigh pumps power

    2 4 6 8 10 12 0.2

    0.4

    0.6

    0.8

    1

    1.2 20160708: Pulling factor vs. Density

    Density, 10 12

    /cm 3

    P u

    lli n

    g f

    a c to

    r

    2 4 6 8 10 12

    0.7

    0.8

    0.9

    1

    1.1 20160708: Pulling factor averaged vs. Density

    Density, 10 12

    /cm 3

    P u

    lli n

    g f

    a c to

    r

    2 4 6 8 10 12 660

    680

    700

    720

    740

    760

    780 20160708: Beat−note span vs. Density

    Density, 10 12

    /cm 3

    F re

    q u

    e n

    c y ,

    M H

    z

    2 4 6 8 10 12 −68

    −66

    −64

    −62

    −60 20160708: Beat−note amplitude vs. Density

    Density, 10 12

    /cm 3

    B e

    a t−

    n o

    te a

    m p

    lit u

    d e

    , d

    B m

    Eugeniy E. Mikhailov (W&M) Towards fast gyroscope LPHYS, 2016 13 / 17

  • Gyroscope laser multi-mode structure

    Gyro beatnote spectrum vs. empty cavity offset

    Empty cavity detuning, MHz

    B e a tn

    o te

    f re

    q u e n c y , M

    H z

    0 20 40 60 80 100 120 140 160

    −400

    −300

    −200

    −100

    0

    −100 −80 −60

    −400

    −350

    −300

    −250

    −200

    −150

    −100

    −50

    0

    50

    dBm

    F re

    q u e n c y , M

    H z

    Cell temperature 110◦C, total power 350 mW. Modes pulling factors are 0.54, 0.45, 0.04.

    Eugeniy E. Mikhailov (W&M) Towards fast g