Lasing of N2+ at 428 nm is studied as a function of the delay dt between two 800 nm ultrashort pumping pulses from a Ti:sapphire laser. This lasing corresponds to a population-inverted transition between levels B2Σu+(0) and X2Σg+(1) of a singly ionized nitrogen molecule. An important erasing of laser emission is observed under pumping with two consecutive pulses separated by large delays −20 ps < dt < +20 ps. From an analysis of the quenching results, we conclude that the mechanism of lasing corresponds to a coherent two-photon amplification scheme. Our results show that a two-photon process can dominate over a population-inverted one-photon amplification.

1.
A.
Couairon
and
A.
Mysyrowicz
, “
Femtosecond filamentation in transparent media
,”
Phys. Rep.
441
,
47
189
(
2007
).
2.
J.
Yao
,
G.
Li
,
C.
Jing
,
B.
Zeng
,
W.
Chu
,
J.
Ni
,
H.
Zhang
,
H.
Xie
,
C.
Zhang
,
H.
Li
,
H.
Xu
,
S. L.
Chin
,
Y.
Cheng
, and
Z.
Xu
, “
Remote creation of coherent emissions in air with two-color ultrafast laser pulses
,”
New J. Phys.
15
,
023046
(
2013
).
3.
Y.
Liu
,
Y.
Brelet
,
G.
Point
,
A.
Houard
, and
A.
Mysyrowicz
, “
Self-seeded lasing in ionized air pumped by 800 nm femtosecond laser pulses
,”
Opt. Express
21
,
22791
22798
(
2013
).
4.
H.
Zhang
,
C.
Jing
,
J.
Yao
,
G.
Li
,
B.
Zeng
,
W.
Chu
,
J.
Ni
,
H.
Xie
,
H.
Xu
,
S. L.
Chin
,
K.
Yamanouchi
,
Y.
Cheng
, and
Z.
Xu
, “
Rotational coherence encoded in an ‘air-laser’ spectrum of nitrogen molecular ions in an intense laser field
,”
Phys. Rev. X
3
,
041009
(
2013
).
5.
H.
Xu
,
E.
Lötstedt
,
A.
Iwasaki
, and
K.
Yamanouchi
, “
Sub-10-fs population inversion in N2+ in air lasing through multiple state coupling
,”
Nat. Commun.
6
,
8347
(
2015
).
6.
H.
Li
,
M.
Hou
,
H.
Zang
,
Y.
Fu
,
E.
Lötstedt
,
T.
Ando
,
A.
Iwasaki
,
K.
Yamanouchi
, and
H.
Xu
, “
Significant enhancement of N2+ lasing by polarization-modulated ultrashort laser pulses
,”
Phys. Rev. Lett.
122
,
013202
(
2019
).
7.
J.
Yao
,
S.
Jiang
,
W.
Chu
,
B.
Zeng
,
C.
Wu
,
R.
Lu
,
Z.
Li
,
H.
Xie
,
G.
Li
,
C.
Yu
,
Z.
Wang
,
H.
Jiang
,
Q.
Gong
, and
Y.
Cheng
, “
Population redistribution among multiple electronic states of molecular nitrogen ions in strong laser fields
,”
Phys. Rev. Lett.
116
,
143007
(
2016
).
8.
X.
Zhong
,
Z.
Miao
,
L.
Zhang
,
Q.
Liang
,
M.
Lei
,
H.
Jiang
,
Y.
Liu
,
Q.
Gong
, and
C.
Wu
, “
Vibrational and electronic excitation of ionized nitrogen molecules in intense laser fields
,”
Phys. Rev. A
96
,
043422
(
2017
).
9.
Q.
Zhang
,
H.
Xie
,
G.
Li
,
X.
Wang
,
H.
Lei
,
J.
Zhao
,
Z.
Chen
,
J.
Yao
,
Y.
Cheng
, and
Z.
Zhao
, “
Sub-cycle coherent control of ionic dynamics via transient ionization injection
,”
Commun. Phys.
3
,
50
(
2020
).
10.
A.
Mysyrowicz
,
R.
Danylo
,
A.
Houard
,
V.
Tikhonchuk
,
X.
Zhang
,
Z.
Fan
,
Q.
Liang
,
S.
Zhuang
,
L.
Yuan
, and
Y.
Liu
, “
Lasing without population inversion in N2+
,”
APL Photonics
4
,
110807
(
2019
).
11.
V.
Tikhonchuk
,
Y.
Liu
,
R.
Danylo
,
A.
Houard
, and
A.
Mysyrowicz
, “
Theory of femtosecond strong field ion excitation and subsequent lasing in N2+
,”
New J. Phys.
23
,
023035
(
2021
).
12.
M.
Richter
,
M.
Lytova
,
F.
Morales
,
S.
Haessler
,
O.
Smirnova
,
M.
Spanner
, and
M.
Ivanov
, “
Rotational quantum beat lasing without inversion
,”
Optica
7
,
586
592
(
2020
).
13.
M.
Lytova
,
M.
Richter
,
F.
Morales
,
O.
Smirnova
,
M.
Ivanov
, and
M.
Spanner
, “
N2+ lasing: Gain and absorption in the presence of rotational coherence
,”
Phys. Rev. A
102
,
013111
(
2020
).
14.
V.
Tikhonchuk
,
Y.
Liu
,
R.
Danylo
,
A.
Houard
, and
A.
Mysyrowicz
, “
Modeling of the processes of ionization and excitation of nitrogen molecules by short and intense laser pulses
,”
Phys. Rev. A
104
,
063116
(
2021
).
15.
L.
Xu
,
Q.
Lu
,
V. T.
Tikhonchuk
,
B.
Zhou
,
R.
Yang
,
Q.
Liang
,
F.
He
,
R.
Danylo
,
A.
Houard
,
A.
Mysyrowicz
, and
Y.
Liu
, “
Quantum and quasi-classical effects in the strong field ionization and subsequent excitation of nitrogen molecules
,”
Opt. Express
30
,
38481
38491
(
2022
).
16.
C.
Kleine
,
M.-O.
Winghart
,
Z.-Y.
Zhang
,
M.
Richter
,
M.
Ekimova
,
S.
Eckert
,
M. J.
Vrakking
,
E. T.
Nibbering
,
A.
Rouzée
, and
E. R.
Grant
, “
Electronic state population dynamics upon ultrafast strong field ionization and fragmentation of molecular nitrogen
,”
Phys. Rev. Lett.
129
,
123002
(
2022
).
17.
R.
Danylo
,
G.
Lambert
,
Y.
Liu
,
V.
Tikhonchuk
,
A.
Houard
, and
A.
Mysyrowicz
, “
Quantum erasing of laser emission in N2+
,”
Opt. Lett.
45
,
4670
4673
(
2020
).
18.
M.
Britton
,
M.
Lytova
,
D. H.
Ko
,
A.
Alqasem
,
P.
Peng
,
D. M.
Villeneuve
,
C.
Zhang
,
L.
Arissian
, and
P. B.
Corkum
, “
Control of N2+ air lasing
,”
Phys. Rev. A
102
,
053110
(
2020
).
19.
A.
Zhang
,
M.
Lei
,
J.
Gao
,
C.
Wu
,
Q.
Gong
, and
H.
Jiang
, “
Subfemtosecond-resolved modulation of superfluorescence from ionized nitrogen molecules by 800-nm femtosecond laser pulses
,”
Opt. Express
27
,
14922
14930
(
2019
).
20.
R.
Danylo
,
G.
Lambert
,
Y.
Liu
,
V.
Tikhonchuk
,
A.
Houard
, and
A.
Mysyrowicz
, “
Time-resolved study of laser emission in nitrogen gas pumped by two near IR femtosecond laser pulses
,”
Opt. Lett.
46
,
1253
1256
(
2021
).
21.
Y.
Fu
,
J.
Cao
,
S.
Wang
,
S.
Chen
,
H.
Zang
,
H.
Li
,
E.
Lötstedt
,
T.
Ando
,
A.
Iwasaki
,
K.
Yamanouchi
, and
H.
Xu
, “
Extremely enhanced N2+ lasing in a filamentary plasma grating in ambient air
,”
Opt. Lett.
46
,
3404
3407
(
2021
).
22.
S.
Mitryukovskiy
,
Y.
Liu
,
A.
Houard
, and
A.
Mysyrowicz
, “
Re-evaluation of the peak intensity inside a femtosecond laser filament in air
,”
J. Phys. B
48
,
094003
(
2015
).
23.
X.-L.
Liu
,
W.
Cheng
,
M.
Petrarca
, and
P.
Polynkin
, “
Measurements of fluence profiles in femtosecond laser filaments in air
,”
Opt. Lett.
41
,
4751
4754
(
2016
).
24.
J.
Gui
,
D.
Zhou
,
X.
Zhang
,
Q.
Lu
,
Y.
Luo
,
Q.
Liang
,
R.
Danylo
,
A.
Houard
,
A.
Mysyrowicz
, and
Y.
Liu
, “
Quenching effect of O2 on cavity-free lasing of N2 pumped by femtosecond laser pulses
,”
Acta Photon. Sin.
49
,
173
(
2020
).
25.
G.
Li
,
C.
Jing
,
B.
Zeng
,
H.
Xie
,
J.
Yao
,
W.
Chu
,
J.
Ni
,
H.
Zhang
,
H.
Xu
,
Y.
Cheng
, and
Z.
Xu
, “
Signature of superradiance from a nitrogen-gas plasma channel produced by strong-field ionization
,”
Phys. Rev. A
89
,
033833
(
2014
).
26.
Y.
Liu
,
P.
Ding
,
G.
Lambert
,
A.
Houard
,
V.
Tikhonchuk
, and
A.
Mysyrowicz
, “
Recollision-induced superradiance of ionized nitrogen molecules
,”
Phys. Rev. Lett.
115
,
133203
(
2015
).
27.
J.-F.
Ripoche
,
G.
Grillon
,
B.
Prade
,
M.
Franco
,
E.
Nibbering
,
R.
Lange
, and
A.
Mysyrowicz
, “
Determination of the time dependence of N2 in air
,”
Opt. Commun.
135
,
310
314
(
1997
).
28.
E. T. J.
Nibbering
,
G.
Grillon
,
M. A.
Franco
,
B. S.
Prade
, and
A.
Mysyrowicz
, “
Determination of the inertial contribution to the nonlinear refractive index of air, N2, and O2 by use of unfocused high-intensity femtosecond laser pulses
,”
J. Opt. Soc. Am. B
14
,
650
660
(
1997
).
29.
Y.-H.
Chen
,
S.
Varma
,
A.
York
, and
H. M.
Milchberg
, “
Single-shot, space- and time-resolved measurement of rotational wavepacket revivals in H2,D2, N2,O2, and N2O
,”
Opt. Express
15
,
11341
11357
(
2007
).
30.
C.
Guo
,
M.
Li
,
J. P.
Nibarger
, and
G. N.
Gibson
, “
Single and double ionization of diatomic molecules in strong laser fields
,”
Phys. Rev. A
58
,
R4271(R)
(
1998
).
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