OR, XNOR, and NAND Optical Logic Gates in Mach-Zehnder Waveguiding Structure Consisting of Nonlinear Material

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INTERNATIONAL JOURNAL OF MICROWAVE AND OPTICAL TECHNOLOGY,
VOL.13, NO.5, SEPTEMBER 2018
OR, XNOR, and NAND Optical Logic Gates in MachZehnder Waveguiding Structure Consisting of Nonlinear
Material
Muhimmatul Khoiro*, Melania Suweni Muntini, Yono Hadi Pramono
Department of Physics, Faculty of Science
Institut Technology of Sepuluh Nopember, Surabaya, Indonesia
E-mail: [email protected]; [email protected]
Abstract-OR, XNOR, and NAND optical logic gates
in Mach-Zehnder waveguiding structure consisting
of nonlinear material had been analyzed by means
of Finite Difference Beam Propagation Method (FDBPM). Nonlinear material is assumed to be a Kerrlike material which has a refractive index changes
depending on the intensity of the local electric field
from the input beam power. Here we use Organosol
SnO2 as film of waveguide. The Cladding is
composed of linear material which has a little
different with the film refractive index such as Flint
Glass. The proposed waveguide is included by three
input beams. Port 1 and 3 contribute as control
signal which stable input power of 1 W/m and center
input as input signal has varied power input value
between 0 to 20 W/m. Output signal has measured
just in port 5 (center output port). By investigation
of the output power, the proposed structure of
waveguide can generate optical logic for OR, XNOR
and NAND operation. This paper represents that
multi-functional devices such as OR, XNOR and
NAND operation would also be possible in a single
optical waveguide.
Index Terms- Nonlinear material, Mach-Zehnder
waveguide, optical logic gates, FDBPM.
I. INTRODUCTION
Along with technology advanced recently, it
required ultra-high-speed signal processing device
for communication and information system
requirement. Devices which contain nonlinear
material, can be promising solution. These
materials have highly potential to be applied on
super-fast optical signal switching process. This
switching process has speed of a terabit per second
when using fastness recombination and interaction
of photons using nonlinear materials [1]. Some of
nonlinear material which have high possibility for
that application, is SnO2 dan TiO2 [2]–[3]. When
the nonlinear materials are induced by high
intensity of electric field, refractive index of the
materials will change and enlarge self-focusing or
self-routing in the materials. This index of
refractive-dependent changes is expected to be
utilized in various of optical devices to operate at
high bit rates.
One of the optical devices which have been widely
utilizing nonlinear materials is waveguides.
Nonlinear waveguides have been developed for
various functions such as switching and optical
logic gates on various structures of waveguides.
The function of the waveguide as an optical
switching is similar to the optical switching
process in fiber coupling that has been done in
previous research [4]. The learning of basic
structure for analyzing optical switching process
has been applied such as in the directional couplers, X-crossing, Y-branching, even by utilizing
nonlinear uniform medium [5]–[10] . Furthermore, the waveguides are expected to be combined
with other optical devices such as a combination
of optical switching with antennas that have been
performed in previous studies [11]–[12].
Nonlinear waveguides have also been used for
many optical logic gate applications. This optical
logic gate is applied to various structure of waveguide, such as symmetry X-crossing waveguide
and asymmetry Y-branching waveguide and
Mach-Zehnder waveguide [13]–[17]. However,
each optical logic gate function is obtained by
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changing the structure or parameter of waveguides.
In this paper, a nonlinear waveguide is proposed
for optical logic gates applications with fixed
structures and parameters. The Mach-zehnder
structure has two arms. If one or both arms are
given pertubation effect, there will be a phase
waveguide and radiation loss as experienced by
using S and Y structures. The advantages of this
structure is good bandwidth, smaller size, high
fabrication tolerance and best balance of power
[18]. This structure has better performance of
sensitivity to wavelength and temperature than the
structure of Microring Resonator [19].
II. CHARACTERISTICS OF WAVEGUIDE
The proposed waveguide structure is composed of
the waveguide shaped Mach-Zehnder with two
straight control waveguide as shown in fig.1. In
output regions, the separation distances are
arranged by providing a certain angle (2) to avoid
coupling between waveguides. It contains of
nonlinear material as film/guide parts and linear
material as cladding while the parameters is
shown in table 1. The width of the waveguide's
guide parts is equal to d1 = 2 mikrometers, except
for the width in the Mach Zehnder's arms as d2=1
mikrometers. This parameter is chosen because to
create a single-mode waveguides.
The films of the waveguide contains a nonlinear
material assumed as a kerr type materials. While
the substrate of this waveguide is a homogeneous
linear materials. Therefore, the refractive index of
the film will change according to the intensity of
the applied electric field according to the
following equation:
n f  n 2fl   E
Fig.1.
Proposed waveguide structure
Table 1: Fixed parameter of the proposed structur of
micro-ring resonator waveguide
Parameter
Waveguide length
Mach-Zehnder’s arms length
Waveguide width
Straight waveguide thickness
Mach-zehnder’s thickness
Gap
Angle of MZ branches
Angle of output waveguides
Refractive index of film
Refrative index of cladding
Nonlinear coefficient
Wavelength
Waveguide length of output port
Value
L = 4250 µm
Lg = 2500 µm
W = 150 µm
d1 = 2,0 µm
d2 = 1,0 µm
g = 7,18172 µm
θ1 = 1o
θ2 = 0,25o
nf = 2,011
nc = 2,006
α = 1,7 x 10-11 m2/V2
λ = 1,06 µm
Lout = 1000 µm
2
(1)
The higher intense of the electric field, the higher
the refractive index when α is positive. The
waveguide is also assumed to be homogeneous
along the y-axis, so  / y  0 . The wave equation
is represented by the electric field Ey, the TE mode
inside along the waveguide consisting the
nonlinear Kerr-Like medium is
 2 E y   0 0 n 2
2 Ey
t 2
 0
 2 PNL
t 2
(2)
Where  0 and 0 is permitivity and permeability
on free space and PNL is third order nonlinear
polarization which given by equation:
PNL   0   3 E y3
(3)
In this research, organosol SnO2 material was
selected as a nonlinear material which formed
waveguide by refractive index, nf = 2,011 as a film
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and nc = 2,006 as cladding and nonlinear
coefficient α = 1,7 x 10-11 m2/V2. While the
waveguide is inserted by input beam with
wavelength response, λ = 1.06 µm [20]. The basic
mode propagation constant, TE0 in the input port
has been calculated using the numerical method as
β/k0 = 2,00789266697578 (k0 is wavenumber in
free space).
The proposed waveguide is numerically analyzed
using FD-BPM (Finite Difference Beam
Propagration Method). The analyzed is made in
region |x| < xmax (= 25 μm) by calculating the
homogeneous grid with interval Δx = 0.05 μm in
tranverse coordinate and interval Δz = 1 μm in
direction of propagation. The input power is
evaluated by electric field integrals generated by
the iteration process along the x axis in the device
area and the output power is evaluated from the
thickness of each channel in the waveguide [6]. As
a logic gate application, the efficiency η is only
calculated on the output power of port 5 compared
to the total input power given in the following
equation:

Pout ,5
respon at power of 5,10 W/m. It is characterized
by an irregular value of output power. The lowest
output power value is obtained at input power of
18,10 W/m, which is about 0,21 W/m. This
indicates that on this input power, the each signal
after input branch has a phase shift. The phase
difference of both signals reaches the maximum.
Therefore after the two signals are reunited on the
output branch, both signals have interference
which debilitating each other (destructive).
Figure 3-6 shows the wave propagation behavior
on the waveguides by input power of 18,1 W/m.
These figures provide a waveguide application as
function of OR logic gate, as shown in table 2. The
output power is obtained with a certain value by
turning on control signals from either one or both.
When one control signal is applied, the signal on
one of the Mach-Zehnder's arms near the straight
waveguide which passed by the control signal,
will be disturbed. It can interfere shift of phase
signals. Thus, the phase difference of signals on
both sides of Mach-Zehnder's arms doesn't reach
the maximum and interference between both of
them doesn't completely eliminate each other. It
also happens when both control signals are given.
(4)
Pin
12
III. RESULT AND DISCUSSION
The following figures show wave propagation on
the proposed waveguides. Input beams through
three ports namely ports 1, 2, and 3, where ports 1
and 3 are control signal ports that act as logic gate
controls. On both these ports only have two states
that state "1" if the port is given signal, and state
"0" if the signal is turned off. The control signal
given on ports 1 and 3 has a fixed signal power of
1 W/m. While port 2 serves as a port input signal.
In this port the signal is always supplied but with
the power intentionally changed.
Figure 2 shows the output power characteristics
when the input power is applied to the machzehnder waveguide without control signal power
from both straight waveguides. The graph shows
that the nonlinearity of the waveguide starts to
Output Power, Pout (W/m)
10
8
6
4
2
0
0
2
4
6
8
10
12
14
16
18
20
Input Signal Power, Pin (W/m)
Fig.2.
Charactistics of output power when control
power is turned off
By turned on one of the control signals, the input
signal from one of the mach zehnder's arms near
the straight waveguide which is passed by the
control signal, is interrupted by the pertubation
between both of signals and give affect to phase
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shift of the input signal. The effects of pertubati on
begins to observe from the input power of 3,5
W/m where the output power value begins to
decrease slightly, as shown in Figure 7. The
oscillation of output power value increase on the
input power above 4,2 W/m because followed by
the response of nonlinearity material on
waveguide.
Fig.6.
Propagating of light waves in the OR gate
when input power in port 2 = 18,10 W/m and
control signal in both ports 1 and 3
Figure 7 shows that the control signals at port 1
(straight line) and at port 2 (dashed line) have dif-
Table 2: On-off states and output power for OR gate on
proposed waveguide
Input power
Port 1
Port 2
0
0
1
0
0
1
1
1
Propagating of light waves in the OR gate
when input power in port 2 = 18,10 W/m and
no control signal
12
Output Power, Pout (W/m)
Fig.3.
Output Power (Port 5)
State
Power (W/m)
0
0,21
1
1,77
1
6,77
1
1,67
10
8
6
4
2
0
0
2
4
6
8
10
12
14
16
18
20
Input Signal Power, Pin (W/m)
Port 1 is turned on
Fig.7.
Fig.4.
Fig.5.
Propagating of light waves in OR gate when
input power in port 2 = 18,10 W/m and
control signal only in port 1
Propagating of light waves in the OR gate
when input power in port 2 = 18,10 W/m and
control signal only in port 3
Port 2 is turned on
Charactistics of output power when one of
control power is turned on
ferent output power characteristics. This can be
due to the nonlinear material effects already
embedded in the input waveguide (before
branching) giving a phase shift on each part of the
input signal. So the signals that divided into
branches already have different characteristics,
also give different responses to the disturbance of
the control signals. This difference occurs only
after a fairly high power input, which in this case
occurs after the input power of 4 W / m. This is
also the reason why the output power on the OR
logic gate especially when one of port 1 and port
2 is turned on, has a pretty much different value.
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The lowest output power by giving one of the
control signals occurs at an input power of 15
W/m. Using the input power, the waveguide appli
cation is obtained as a function of XNOR optical
logic gate, as shown by the wave propagation in
Fig. 8-11 while the output power values for each
state are also shown in Table 3.
Fig.11.
Propagating of light waves in the XNOR
gate when input power in port 2 = 15 W/m
and control signal in both ports 1 and 3
Table 3: On-off states and output power for XNOR gate
on proposed waveguide
Fig.8.
Input power
Port 1
Port 2
0
0
1
0
0
1
1
1
Propagating of light waves in the XNOR
gate when input power in port 2 = 15 W/m
and no control signal
Output Power (Port 5)
State
Power (W/m)
1
6,96
0
0,05
0
0,15
1
3,28
14
Output Power, Pout (W/m)
12
10
8
6
4
2
0
0
Fig.9.
Fig.10.
Propagating of light waves in the XNOR
gate when input power in port 2 = 15 W/m
and control signal only in ports 1
Propagating of light waves in the XNOR
gate when input power in port 2 = 15 W/m
and control signal only in ports 3
2
4
6
8
10
12
14
16
18
20
Input Signal Power, Pin (W/m)
Fig.12.
Charactistics of output power when both of
control power is turned on
The oscillation frequency of the output power
value is greater when both control signals are
turned on, as shown in Figure 12. The value of the
output power has already begun to oscillate, even
in a small input power of 3,4 W/m. It is due to the
pertubation effect of both control signals through
straight waveguides and also the nonlinear
material effect which is contained on the
waveguide.
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Fig.13.
Propagating of light waves in the NAND
gate when input power in port 2 = 18,70
W/m and no control signal
Fig.16.
Propagating of light waves in the NAND
gate when input power in port 2 of 18,70
W/m and control signal in both ports 1 and 3
Table 4: On-off states and output power for NAND gate
on proposed waveguide
Input power
Port 1
Port 2
0
0
1
0
0
1
1
1
Fig.14.
Fig.15.
Propagating of light waves in the NAND
gate when input power in port 2 = 18,70
W/m and control signal only in port 1
Propagating of light waves in the NAND
gate when input power in port 2 = 18,70
W/m and control signal only in port 3
Figure 13-16 shows wave propagation on the
waveguide with an input power of 18,70 W/m,
where the output power reaches the minimum
value using the input power when both control
signals are turned on. However, the output power
is still measurable in other states. So the
waveguide can be used as a function of optical
logic gate NAND, as shown in table 4.
For the result shown above, it confirmed that the
proposed waveguide structure could function as
varied optical logic, i.e. OR, XNOR and NAND
Output Power (Port 5)
State
Power (W/m)
1
1,37
1
4,87
1
6,28
0
0,09
operation. The operations realize just by varying
power input. Here, we doesn’t need to change
either waveguide structure or properties of
waveguide material like previous researches. The
comparation result with previous research has
been shown in Table 5. The paper represent that
the multi-functional device can be possible
operated in a single optical waveguide.
In order to allow a true comparison, we propose to
compare our results and those obtained in [13].
The two studied systems have the same design
except output region in our design has adjusted to
avoid coupling effect between waveguides.
Moreover, the two systems have difference in
placed of nonlinear material. In reference [13],
nonlinear material consisted just on MachZehnder’s arms. In table 5 present a comparison of
optical logic gates that obtained by input power
applied in waveguides. It shows a good agreement
between both structures. Although both structure
obtains XNOR logic application in 15W/m, the
proposed waveguide can obtain another logic
operation in other input power. It shows that the
proposed waveguide represents multi-functional
device in single waveguide.
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Table 5: Comparasion of results obtain for proposed
structure waveguide and reference [13]
Input Power
Optical logic
Operation
References
Waveguide [13]
15,00 W/m
XNOR
Proposed
Waveguide
15,00 W/m
18,10 W/m
18,70 W/m
XNOR
OR
NAND
[3]
[4]
VI. CONCLUSION
OR, XNOR, and NAND optical logic gates in
Mach-Zehnder waveguiding structure consisting
of nonlinear material had been analyzed by means
of Finite Difference Beam Propagation Method
(FD-BPM). The change of input power causes
changeable value of the output power. Due to the
nonlinearity effect on waveguides material and the
perturbation effect of the control signal which
through the straight waveguides, it causes
different output power responses on each input
power and under different states. By investigation
of the output power, OR optical logic gates are
obtained by input signal of 18,1 W/m, XNOR
optical logic gate by input signal of 15 W/m and
an optical logic NAND gate by input signal of 18,7
W/m. This paper represents that multi-functional
devices such as OR, XNOR and NAND operation
would also be possible in a single optical
waveguide.
[5]
[6]
[7]
[8]
[9]
ACKNOWLEDGMENT
The authors are thankful to PMDSU (Master Pogram of
Education Leading to Doctoral Degree for Excellent
Graduates) scholarship by DIKTI.
[10]
REFERENCES
[1]
[2]
K. Al-hemyari, J. S. Aitchison, C. N. Ironside, G.
T. Kennedy, R. S. Grant, and W. Sibbett, “Ultrafast
all-optical switching in GaAlAs integrated
interferometer in 1.55 μm spectral region,”
Electronics Letters, vol. 28, no. 12, p. 1090, June
1992.
G. Yudoyono, N. Ichzan, V. Zharvan, R. Daniyati,
H. Santoso, B. Indarto, Y. H. Pramono, M. Zainuri,
[11]
[12]
and Darminto, “Effect of calcination temperature
on the photocatalytic activity of TiO2 powders
prepared by co-precipitation of TiCl3,” AIP Conf.
Proc. 1725, p. 020099, Apr. 2016.
G. Yudoyono, Y. H. Pramono, M. Zainuri, and D.
Darminto, “Optical properties
of TiO2
nanorod/PMMA bilayered film and the application
for anti-reflection,” Micro & Nano Letters, vol. 12,
no. 10, pp. 787–792, Oct. 2017.
S. Samian, Y. H. Pramono, A. Y. Rohedi, A. Y.
Rusydi, and A. H. ZAIDAN, “Theoretical and
experimental study of fiber-optic displacement
sensor using multimode fiber coupler,” Journal of
Optoelectronics and Biomedical Materials, vol. 1,
no. 3, pp. 303–308, Sept. 2009.
T. Ahmadi Tameh, B. M. Isfahani, N. Granpayeh,
and A. M. Javan, “Improving the performance of
all-optical switching based on nonlinear photonic
Crystal microring resonators,” AEU - International
Journal of Electronics and Communications, vol.
65, no. 4, pp. 281–287, Apr. 2011.
Y. H. Pramono, M. Geshiro, T. Kitamura, and S.
Sawa, “Self-Switching in Crossing Waveguides
with Three Channels Consisting of Nonlinear
Material,” IEICE Transactions on Electronics, vol.
E82–C, no. 1, pp. 111–118, Jan. 1999.
Y.-D. Wu, M.-H. Chen, S.-Y. Chen, and K.-H.
Chiang, “A new all-optical switch by using the
nonlinear asymmetric Mach-Zehnder waveguide
structure,” In Nonlinear Optical Phenomena and
Applications, International Society for Optics and
Photonics, vol. 5646, pp. 325-334, Jan. 2005.
Y.-D. Wu, “New all-optical switch based on the
spatial soliton repulsion,” Optics express, vol. 14,
no. 9, pp. 4005–4012, Jan. 2006.
N. A. Siddiq, M. Khoiro, M. S. Muntini, and Y. H.
Pramono, “All-optical logic gates based optimized
XY-branch waveguide utilizing SnO2 nonlinear
material,”
in
Sensors,
Instrumentation,
Measurement and Metrology (ISSIMM), 2017
IEEE International Seminar, pp. 169–173, Aug.
2017.
M. Khoiro, N. A. Siddiq, J. Annovasho, M. S.
Muntini, and Y. H. Pramono, “All-optical logic
gates in directional coupler waveguide consisting
of nonlinear material,” in Sensors, Instrumentation,
Measurement and Metrology (ISSIMM), 2017
IEEE International Seminar on, pp. 174–179, Aug.
2017.
E. R. Kusumawati, Y. H. Pramono, and A.
Rubiyanto, “Design and fabrication of tunable
microstrip antenna using photodiode as optical
switching
controlled
by
Infrared,”
in
Communication,
Networks
and
Satellite
(COMNETSAT), 2013 IEEE International
Conference on, pp. 55–58, Dec. 2013.
E. R. Kusumawati, Y. H. Pramono, and A.
Rubiyanto, “Design and fabrication of low-cost
IJMOT-2018-6-1591 © 2018 IAMOT
469
INTERNATIONAL JOURNAL OF MICROWAVE AND OPTICAL TECHNOLOGY,
VOL.13, NO.5, SEPTEMBER 2018
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
reconfigurable
microstrip
antenna
using
photodiode as optical switching,” in AIP
Conference Proceedings, pp. 67–70, Sept. 2014.
Y. H. Pramono and Endarko, “Nonlinear
waveguides for optical logic and computation,”
Journal of Nonlinear Optical Physics & Materials,
vol. 10, no. 02, pp. 209–222, Jun. 2001.
Y. H. Pramono, M. Geshiro, T. Kitamura, and S.
Sawa, “Optical logic OR-AND-NOT and NOR
gates in waveguides consisting of nonlinear
material,” IEICE transactions on electronics, no.
11, pp. 1755–1760, Jan. 2000.
Y.-D. Wu, T.-T. Shih, and M.-H. Chen, “New alloptical logic gates based on the local nonlinear
Mach-Zehnder interferometer,” Optics Express,
vol. 16, no. 1, pp. 248–257, Jan. 2008.
T. Yabu, M. Geshiro, T. Kitamura, K. Nishida, and
S. Sawa, “All-optical logic gates containing a twomode nonlinear waveguide,” IEEE Journal of
Quantum electronics, vol. 38, no. 1, pp. 37–46, Jan.
2002.
S. Medhekar and P. P. Paltani, “Novel All-Optical
Switch
Using
Nonlinear
Mach-Zehnder
Interferometer,” Fiber and Integrated Optics, vol.
28, no. 3, pp. 229–236, May 2009.
A. R. Hanim, “Pemodulat optik interferometer
mach zehnder (MZI) suntikan pembawa di atas
silikon-di atas-penebat (SOI),” UTeM, July 2014.
J. Ding, L. Yang, Q. Chen, L. Zhang, and P. Zhou,
“Demonstration of a directed XNOR/XOR optical
logic circuit based on silicon Mach–Zehnder
interferometer,” Optics Communications, Aug.
2015.
B. Yu et al., “Third-order nonlinear optical
properties of SnO 2 nanoparticles,” Acta Phys. Sin.
(Overseas Edn), vol. 5, no. 5, p. 377, May 1996.
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