It has been long believed that a total mode conversion between longitudinal and shear elastic waves can only be achieved at a certain incidence angle. Here, we show that a total mode conversion can be achieved for a broad range of incidence angles by a specially designed elastic metasurface, namely, transmodal metasurface. From the generalized reflection law, we found that the incident longitudinal wave can be totally converted to a reflected shear wave over a broad range of incidence angles if a sufficiently large phase gradient is introduced at the boundary. Numerical and experimental investigations with a specially engineered transmodal metasurface showed that the total mode conversion can be achieved for wide incidence angles from 19° to 90°, which was impossible to be achieved previously. The proposed idea of the transmodal metasurface can open up an advanced avenue for tailoring elastic wave modes as an outstanding alternative to generating shear waves.

1.
J. D.
Achenbach
,
Wave Propagation in Elastic Solids
(
Elsevier
,
New York
,
1984
).
2.
J. L.
Rose
,
Ultrasonic Waves in Solid Media
(
Cambridge University Press
,
New York
,
1999
).
3.
J.
Goodier
and
R.
Bishop
,
J. Appl. Phys.
23
,
124
(
1952
).
4.
C.
Sayers
and
C.
Tait
,
Ultrasonics
22
,
57
(
1984
).
5.
G.
Clement
,
P.
White
, and
K.
Hynynen
,
J. Acoust. Soc. Am.
115
,
1356
(
2004
).
6.
K.
Hynynen
,
N.
McDannold
,
N. A.
Sheikov
,
F. A.
Jolesz
, and
N.
Vykhodtseva
,
Neuroimage
24
,
12
(
2005
).
7.
P.
White
,
G.
Clement
, and
K.
Hynynen
,
Ultrasound Med. Biol.
32
,
1085
(
2006
).
8.
Y.
Tufail
,
A.
Yoshihiro
,
S.
Pati
,
M. M.
Li
, and
W. J.
Tyler
,
Nat. Protoc.
6
,
1453
(
2011
).
9.
K. F.
Graff
,
Wave Motion in Elastic Solids
(
Dover
,
New York
,
1975
).
10.
S. H.
Lee
,
C. M.
Park
,
Y. M.
Seo
,
Z. G.
Wang
, and
C. K.
Kim
,
J. Phys.: Condens. Matter
21
,
175704
(
2009
).
11.
J. H.
Oh
,
H. M.
Seung
, and
Y. Y.
Kim
,
Appl. Phys. Lett.
104
,
073503
(
2014
).
12.
J. H.
Oh
,
Y. E.
Kwon
,
H. J.
Lee
, and
Y. Y.
Kim
,
Sci. Rep.
6
,
23630
(
2016
).
13.
J. H.
Oh
and
B.
Assouar
,
Sci. Rep.
6
,
33410
(
2016
).
14.
Y.
Ding
,
E.
Statharas
,
K.
Yao
, and
M.
Hong
,
Appl. Phys. Lett.
110
,
241903
(
2017
).
15.
F.
Monticone
,
N. M.
Estakhri
, and
A.
Alù
,
Phys. Rev. Lett.
110
,
203903
(
2013
).
16.
A. V.
Kildishev
,
A.
Boltasseva
, and
V. M.
Shalaev
,
Science
339
,
1232009
(
2013
).
17.
Y.
Li
,
B.
Liang
,
Z.
Gu
,
X.
Zou
, and
J.
Cheng
,
Sci. Rep.
3
,
2546
(
2013
).
18.
X.
Wan
,
Y. B.
Li
,
B. G.
Cai
, and
T. J.
Cui
,
Appl. Phys. Lett.
105
,
121603
(
2014
).
19.
K.
Song
,
J.
Kim
,
S.
Hur
,
J.-H.
Kwak
,
S.-H.
Lee
, and
T.
Kim
,
Sci. Rep.
6
,
32300
(
2016
).
20.
W.
Wang
,
Y.
Xie
,
B. I.
Popa
, and
S. A.
Cummer
,
J. Appl. Phys.
120
,
195103
(
2016
).
21.
Y.
Liu
,
Z.
Liang
,
F.
Liu
,
O.
Diba
,
A.
Lamb
, and
J.
Li
,
Phys. Rev. Lett.
119
,
034301
(
2017
).
22.
X.
Su
,
Z.
Lu
, and
A. N.
Norris
,
J. Appl. Phys.
123
,
091701
(
2018
).
23.
Y.
Wu
,
Y.
Lai
, and
Z.-Q.
Zhang
,
Phys. Rev. Lett.
107
,
105506
(
2011
).
24.
R.
Zhu
,
X.
Liu
,
G.
Hu
,
C.
Sun
, and
G.
Huang
,
Nat. Commun.
5
,
5510
(
2014
).
25.
Y.
Noguchi
,
T.
Yamada
,
M.
Otomori
,
K.
Izui
, and
S.
Nishiwaki
,
Appl. Phys. Lett.
107
,
221909
(
2015
).
26.
X.
Su
and
A. N.
Norris
,
J. Acoust. Soc. Am.
139
,
3386
(
2016
).
27.
H.
Zhu
and
F.
Semperlotti
,
Phys. Rev. Lett.
117
,
034302
(
2016
).
28.
J. M.
Kweun
,
H. J.
Lee
,
J. H.
Oh
,
H. M.
Seung
, and
Y. Y.
Kim
,
Phys. Rev. Lett.
118
,
205901
(
2017
).
29.
H. J.
Lee
,
J.-R.
Lee
,
S. H.
Moon
,
T.-J.
Je
,
E.-C.
Jeon
,
K.
Kim
, and
Y. Y.
Kim
,
Sci. Rep.
7
,
15378
(
2017
).
30.
N.
Yu
,
P.
Genevet
,
M.
Kats
,
F.
Aieta
,
J.
Tetienne
,
F.
Capasso
, and
Z.
Gaburro
,
Science
334
,
333
(
2011
).
31.
H. J.
Lee
,
J. K.
Lee
, and
Y. Y.
Kim
,
J. Sound Vib.
353
,
58
(
2015
).
32.
Y. Y.
Kim
and
Y. E.
Kwon
,
Ultrasonics
62
,
3
(
2015
).

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