Developing Continuous-Wave Raman Lasers in Solid para-Hydrogen and Barium Nitrate
William R. Evans
Benjamin J. McCall
Takamasa Momose
Department of PhysicsUniversity of Illinois at Urbana-Champaign
Departments of Chemistry, Astronomy and PhysicsUniversity of Illinois at Urbana-Champaign
Department of ChemistryThe University of British Columbia
Eventual Goal: Mid-Infrared Spectroscopy Many Attractive Targets in 5 – 10 μm Range
Animation from Joel Bowman, Emory University
C60
C3H3+
CH5+
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Eventual Goal: Mid-Infrared Spectroscopy Many Attractive Targets in 5 – 10 μm Range Few Available Widely-Tunable Laser Sources
Want sub-MHz resolution Necessitates cw sources
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Eventual Goal: Mid-Infrared Spectroscopy Many Attractive Targets in 5 – 10 μm Range Few Available Widely-Tunable Laser Sources Stimulated Raman Scattering
Shifting a near-infrared laser into the mid-infrared
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Brief Review of Raman Scattering Pump photon scatters inelastically with an atom
Redshifted to a “Stokes” photon.
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Stimulated Raman Scattering Two-photon process Incoming Stokes stimulates transition Outgoing photons emitted coherently
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Stimulated Raman Scattering Optical cavity enhances process
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Stimulated Raman Scattering Optical cavity enhances process Collect either:
Just Stokes Radiation
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Stimulated Raman Scattering Optical cavity enhances process Collect either:
Just Stokes Radiation Both Pump and Stokes Radiation
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Key Criterion: Threshold Pump Power
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Key Criterion: Threshold Pump Power
Want: Ultra-narrow linewidth
Need cw laser Not high complexity
Lower finesse cavity
Challenges: CW pump lasers have
lower maximum power Lower finesse cavity
means less power buildup in the cavity
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Key Criterion: Threshold Pump Power
How we are going to achieve lasing: Need high Raman gain coefficient
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Options: Solid para-Hydrogen and Barium Nitrate
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Options: Solid para-Hydrogen and Barium Nitrate Transparent for most of 100 nm to 10 μm
M. Fushitani, S. Kuma, Y. Miyamoto, H. Katsuki, T. Wakabayashi, T. Momose, and A.F. Vilesov, Optics Letters, 28, 1, 37 (2003)M. Mengel, B.P. Winnewisser, and M. Winnewisser, Canadian Journal of Physics, 78, 317 (2000)
Options: Solid para-Hydrogen and Barium Nitrate Transparent for most of 100 nm to 10 μm Huge Raman gain
18,000 cm/GW Compare:
2.5 cm/GW for gaseous hydrogen 47 cm/GW for Ba(NO3)2
M. Fushitani, S. Kuma, Y. Miyamoto, H. Katsuki, T. Wakabayashi, T. Momose, and A.F. Vilesov, Optics Letters, 28, 1, 37 (2003)M. Mengel, B.P. Winnewisser, and M. Winnewisser, Canadian Journal of Physics, 78, 317 (2000)
Options: Solid para-Hydrogen and Barium Nitrate Transparent for most of
100 nm to 10 μm Huge Raman gain
18,000 cm/GW Enormous frequency shift
4149.7 cm-1 in solid
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Options: Solid para-Hydrogen and Barium Nitrate Transparent for most of
100 nm to 10 μm Huge Raman gain
18,000 cm/GW Enormous frequency shift
4149.7 cm-1 in solid
Well-established as a Raman medium
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Options: Solid para-Hydrogen and Barium Nitrate Transparent for most of
100 nm to 10 μm Huge Raman gain
18,000 cm/GW Enormous frequency shift
4149.7 cm-1 in solid
Well-established as a Raman medium Highest Raman gain of any room-temp crystal
47 cm/GW
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Options: Solid para-Hydrogen and Barium Nitrate Transparent for most of
100 nm to 10 μm Huge Raman gain
18,000 cm/GW Enormous frequency shift
4149.7 cm-1 in solid
Well-established as a Raman medium Highest Raman gain of any room-temp crystal
47 cm/GW Frequency shift of
1047 cm–1
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Long-Range Goal: Fully-optimized
solid para-hydrogen cw Raman laser tunable between 5 and 10 μm Achievable by pumping with the signal beam from
a cw OPO which is tunable from 1.6 to 1.9 μm Threshold pump power can be minimized by
using actively-locked doubly-resonant high-finesse optical cavity
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Barium Nitrate is a Natural Preparatory Project Despite its obvious promise, solid para-hydrogen
has never been used as a cw Raman shifter. Constructing an actively-locked doubly-resonant
cavity involves some technical complexity that we want to separate from the complexity involved in making a cryogenic crystal.
Barium nitrate is a natural preparatory project. An actively-locked doubly-resonant
barium nitrate Raman shifter has never been constructed.
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Dry N2 Purge Box
Ba(NO3)2 Crystal
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Dry N2 Purge Box
Ba(NO3)2 Crystal
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Dye Laser
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Dye Laser
Coherent 899 Dye Ring Laser22 June 2012
AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
22 June 2012
AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
EOM
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
EOM
New Focus Model 4001 Electro-Optic Phase Modulator
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
EOM
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
EOM
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Locking Electronics
EOM
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Locking Electronics
EOM
CavityTransmission
Error Signal
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Locking Electronics
PZT
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Locking Electronics
PZT
22 June 2012 http://bjm.scs.illinois.edu
AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Locking Electronics
AOM
¼ λ
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
AOM
¼ λLocking
Electronics
Brimrose EM-85-2-1064 Acousto-Optic Modulator
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Dye Laser
Dry N2 Purge Box
Ba(NO3)2 Crystal
PZT
EOM
Locking Electronics
Cryostat
Solid p-H2 Crystal
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AOM
¼ λ
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
Pump Laser
PZT
EOM
Locking Electronics
Cryostat
Solid p-H2 Crystal
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AOM
¼ λ
First Continuous-Wave Solid para-Hydrogen Raman Laser
Pump Laser
PZT
EOM
Locking Electronics
Cryostat
Solid p-H2 Crystal
First Actively-Locked Doubly-Resonant Barium Nitrate Raman Laser
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AOM
¼ λ
First Continuous-Wave Solid para-Hydrogen Raman Laser
Pump Laser
PZT
EOM
Locking Electronics
Cryostat
Solid p-H2 Crystal
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Summary Solid para-hydrogen is an attractive medium
for use in stimulated Raman scattering. A solid para-hydrogen Raman laser pumped
by a cw OPO can cover the 5 – 10 μm portion of the spectrum.
We are constructing the first actively-locked doubly-resonant barium nitrate Raman laser in the visible in preparation for building this system.
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Acknowledgments McCall Research
Group Steve
Kregel Preston
Buscay Heather
Hanson
KristinEvans
The McCall Research Grouphttp://bjm.scs.illinois.edu