Supplemental Document
Giant terahertz polarization rotation in ultrathin
films of aligned carbon nanotubes: supplement
A NDREY B AYDIN , 1,4 N ATSUMI K OMATSU , 1 F UYANG TAY, 1 S AUNAB
G HOSH , 1 TAKUMA M AKIHARA , 2 G. T IMOTHY N OE , 1 AND J UNICHIRO
K ONO 1,2,3,5
1 Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
2 Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
3 Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
4 e-mail: baydin@rice.edu
5 e-mail: kono@rice.edu
This supplement published with The Optical Society on 20 May 2021 by The Authors under the
terms of the Creative Commons Attribution 4.0 License in the format provided by the authors
and unedited. Further distribution of this work must maintain attribution to the author(s) and the
published article’s title, journal citation, and DOI.
Supplement DOI: https://doi.org/10.6084/m9.figshare.14447169
Parent Article DOI: https://doi.org/10.1364/OPTICA.422826
Giant Terahert
T tz Polarrization Rotatio
on in
Ultrathin Films
s of Alig
gned Ca arbon NNanotub
bes:
supplemental document
In addition to
o the polarizattion-dependentt THz time-doomain data forr the main 45--nm thick
CNT film sho own in the main n text, time-do
omain THz wavveforms for annother CNT film m (with a
thickness of 30
3 nm) on a Si S substrate arre shown in F Fig. S1Error! Reference soource not
found.. The left and right panels, (Left)) and (Rightt), respectivelyy, correspond too the two
orientations of
o the output polarizer.
p The input polarizattion was set aalong the -axiis. As the
angle betweeen the carbon nanotube alig gnment directiion and the iinput light polarization
changes, the pulses in thee time-domain n waveform chhange. The m most drastic chhange, as
mentioned in the main text and is the bassis of this workrk, is the disapppearance of thhe second
pulse observeed at ~30 degreees (see Fig. S1
1), which we reefer to as the ‘m
magic angle’.
This angle corresponds
c to
o the disappeearance of thhe second puulse for the output
polarization. Further,
F we dettermined how the magic anglle depends on the CNT film thickness
n Fig. S2. Acccording to Figg. S2a, the magic angle
and the underrlying substratte, as shown in
changes by ab bout 5 degrees when the CNT T film thickneess varies from
m 30 nm to 1000 nm. Fig.
S2b shows th hat increasing the
t refractive index
i of the suubstrate decreaases the magic angle by
about 10 degrrees.
Fig. S1. Time-do omain THz wavefo orms obtained for a 30-nm thick CNTT film. The measuured electric field iis shown as
a function of timee for co-polarized,, (Left), and cou
unter-polarized, (Right), configuurations. The anglee between
the input polarizaation and the align
nment orientation of
o carbon nanotubees is indicated on tthe right.
a b
Fig. S2. The a, CNT
C film thicknesss dependence and the
t b, substrate deependence of the m
magic angle.
As discussed d in the main n text, the ex
xistence of thee magic anglee is explainedd by the
polarization rotation
r of the THz wave upo on transmissioon through andd reflection by the CNT
film. Fig. S3.FFig. S 4. show Faraday
F and Kerr angles (deffined in the maain text) as a fuunction of
the angle betwween the input light polarization and the aliggnment directiion of carbon nnanotubes
for 30-nm thiick CNT films on Si and quaartz substrates,, to complemennt to the data ppresented
for the 45-nmm thick CNT film on Si in thee main text. Inn both cases, thhe angle of polarization
out 20∘ and 11
rotation is abo 10∘ for transmisssion and refleection, respectivvely.
Fig. S3. Polarizattion rotation for th
he 30-nm thick CN NT film on a Si subbstrate. a, The ang le of polarization rrotation
upon transmission through the CNT T film. b, The angle of polarization rrotation upon refleection from the CN
NT film.
Arrows indicate the
t polarization ro otation direction ass the angle, , betw
ween the CNT aliggnment direction annd the
input THz polarizzation changes.
Fig. S 4. Polarizaation rotation for th
he 30-nm thick film m on a quartz subsstrate. a, The anglee of polarization rootation
upon transmission through the CNT T film. b, The angle of polarization rrotation upon refleection from the CN NT film.
Arrows indicate the
t polarization ro otation direction ass the angle, , betw
ween the CNT aliggnment direction annd the
input THz polarizzation changes.
