We report the performance of room temperature terahertz sources based on intracavity difference-frequency generation in mid-infrared quantum cascade lasers with a dual-upper-state (DAU) active region. DAU active region design is theoretically expected to produce larger optical nonlinearity for terahertz difference-frequency generation, compared to the active region designs of the bound-to-continuum type used previously. Fabricated buried heterostructure devices with a two-section buried distributed feedback grating and the waveguide designed for Cherenkov difference-frequency phase-matching scheme operate in two single-mode mid-infrared wavelengths at 10.7 μm and 9.7 μm and produce terahertz output at 2.9 THz with mid-infrared to terahertz conversion efficiency of 0.8 mW/W2 at room temperature.

1.
M.
Tonouchi
,
Nat. Photonics
1
,
97
105
(
2007
).
2.
B. S.
Williams
,
Nat. Photonics
1
,
517
525
(
2007
).
3.
S.
Fathololoumi
,
E.
Dupont
,
C. W. I.
Chan
,
Z. R.
Wasilewski
,
S. R.
Laframboise
,
D.
Ban
,
A.
Matyas
,
C.
Jirauschek
,
Q.
Hu
, and
H. C.
Liu
,
Opt. Express
20
,
3866
3876
(
2012
).
4.
M. A.
Belkin
,
F.
Capasso
,
A.
Belyanin
,
D. L.
Sivco
,
A. Y.
Cho
,
D. C.
Oakley
,
C. J.
Vineis
, and
G. W.
Turner
,
Nat. Photonics
1
,
288
292
(
2007
).
5.
M. A.
Belkin
,
F.
Capasso
,
F.
Xie
,
A.
Belyanin
,
M.
Fischer
,
A.
Wittmann
, and
J.
Faist
,
Appl. Phys. Lett.
92
,
201101
(
2008
).
6.
Q. Y.
Lu
,
N.
Bandyopadhyay
,
S.
Slivken
,
Y.
Bai
, and
M.
Razeghi
,
Appl. Phys. Lett.
99
,
131106
(
2011
).
7.
K.
Vijayraghavan
,
R. W.
Adams
,
A.
Vizbaras
,
M.
Jang
,
C.
Grasse
,
G.
Boehm
,
M. C.
Amann
, and
M. A.
Belkin
,
Appl. Phys. Lett.
100
,
251104
(
2012
).
8.
Q. Y.
Lu
,
N.
Bandyopadhyay
,
S.
Slivken
,
Y.
Bai
, and
M.
Razeghi
,
Appl. Phys. Lett.
101
,
251121
(
2012
).
9.
K.
Vijayraghavan
,
Y.
Jiang
,
M.
Jang
,
A.
Jiang
,
K.
Choutagunta
,
A.
Vizbaras
,
F.
Demmerle
,
G.
Boehm
,
M. C.
Amann
, and
M. A.
Belkin
,
Nat. Commun.
4
,
2021
(
2013
).
10.
Q. Y.
Lu
,
N.
Bandyopadhyay
,
S.
Slivken
,
Y.
Bai
, and
M.
Razeghi
,
Appl. Phys. Lett.
103
,
011101
(
2013
).
11.
Q. Y.
Lu
,
N.
Bandyopadhyay
,
S.
Slivken
,
Y.
Bai
, and
M.
Razeghi
,
Appl. Phys. Lett.
104
,
221105
(
2014
).
12.
Y.
Jiang
,
K.
Vijayraghavan
,
S.
Jung
,
F.
Demmerle
,
G.
Boehm
,
M. C.
Amann
, and
M. A.
Belkin
,
J. Opt.
16
,
094002
(
2014
).
13.
S.
Jung
,
A.
Jiang
,
Y.
Jiang
,
K.
Vijayraghavan
,
X.
Wang
,
M.
Troccoli
, and
M. A.
Belkin
,
Nat. Commun.
5
,
4267
(
2014
).
14.
Q. Y.
Lu
,
S.
Slivken
,
N.
Bandyopadhyay
,
Y.
Bai
, and
M.
Razeghi
,
Appl. Phys. Lett.
105
,
201102
(
2014
).
15.
J.
Faist
,
M.
Beck
,
T.
Aellen
, and
E.
Gini
,
Appl. Phys. Lett.
78
,
147
149
(
2001
).
16.
K.
Fujita
,
T.
Edamura
,
S.
Furuta
, and
M.
Yamanishi
,
Appl. Phys. Lett.
96
,
241107
(
2010
).
17.
K.
Fujita
,
S.
Furuta
,
T.
Dougakiuchi
,
A.
Sugiyama
,
T.
Edamura
, and
M.
Yamanishi
,
Opt. Express
19
,
2694
2701
(
2011
).
18.
K.
Fujita
,
S.
Furuta
,
A.
Sugiyama
,
T.
Ochiai
,
A.
Ito
,
T.
Dougakiuchi
,
T.
Edamura
, and
M.
Yamanishi
,
Appl. Phys. Lett.
98
,
231102
(
2011
).
19.
K.
Fujita
,
M.
Yamanishi
,
S.
Furuta
,
A.
Sugiyama
, and
T.
Edamura
,
Appl. Phys. Lett.
101
,
181111
(
2012
).
20.
T.
Dougakiuchi
,
K.
Fujita
,
A.
Sugiyama
,
A.
Ito
,
N.
Akikusa
, and
T.
Edamura
,
Opt. Express
22
,
19930
19935
(
2014
).
21.
The energy-diffusion model has been proposed by one (M.Y.) of the authors; M. Yamanishi, unpublished note (
2012
).
22.
K.
Fujita
,
M.
Yamanishi
,
S.
Furuta
,
K.
Tanaka
,
T.
Edamura
,
T.
Kubis
, and
G.
Klimeck
,
Opt. Express
20
,
20647
20658
(
2012
).
23.
K.
Vijayraghavan
,
M.
Jang
,
A.
Jiang
,
X.
Wang
,
M.
Troccoli
, and
M. A.
Belkin
,
IEEE Photonics Technol. Lett.
26
,
391
(
2014
).
24.

The bound-to-continuum active region is comprised of 20 stages of the λ1 = 8.5 μm design followed by 20 stages of the λ2 = 9.3 μm design. The layer sequence of the λ1 = 8.5 μm design, started with the injection barrier, is 41/18/7/55/9/53/11/48/15/37/16/35/16/33/18/31/20/29/24/27/26/27/30/27, and for the λ2 = 9.3 μm is 38/20/9/60/9/59/10/50/11/40/15/34/15/33/16/30/19/30/23/31/25/32/29/30, where InAlAs barrier layers are in bold, InGaAs quantum well layers in roman, doped layers (Si, 1.2 × 1017 cm−3) are underlined.

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