VOL. 11, NO. 6, MARCH 2016 ISSN 1819-6608
ARPN Journal of Engineering and Applied Sciences
© 2006-2016 Asian Research Publishing Network (ARPN). All rights reserved.
www.arpnjournals.com
3796
ENERGY EFFICIENT DESIGN OF LASER DRIVER USING FIELD
PROGRAMMING GATE ARRAY
Bhagwan Das
1
, M. F. L Abdullah
1
, Mohd Shah Nor Shahida
1
, Qadir Bakhsh
1
and Bishwajeet Pandey
2
1
Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, Parit Jaja, Batu Pahat, Malaysia
2
Chitkara University Research and Innovation Network, Punjab, India
E-Mail: he130092@siswa.uthm.edu.my
ABSTRACT
The laser drivers are extremely important to be used to provide safe interface for the optical components attached
to the laser. In this paper, energy efficient laser driver circuit is design using field programming gate array (FPGA). The
laser driver is first designed using current mode logic (CML) technique, which is widely used for designing the optical
components. Then this design is implemented on FPGA using very large scale integration (VLSI). The laser driver
produces the energy efficient output using voltage scaling technique in which the core voltage of FPGA virtex-7 board is
reduced from 2.2 V (Peak core voltage of FPGA) to 0.5 V (base voltage of FPGA). By reducing core voltage of FPGA
virtex-7 from peak to base voltage the power consume by laser drivers is reduced up to 90% for 15 THz frequency.
Similarly, for less than 15 THz frequencies the power consumption is also reduced. The main advantage of designing this
energy efficient laser driver is that it will control the output of any high frequency semiconductor laser up to 15 THz
frequency. This energy efficient design of laser driver will be integrated with high frequency semiconductor laser to
produce green optical output for communication systems.
Keywords: current mode logic, core voltage of FPGA, voltage scaling technique, laser driver, power reduction, field programming gate
array.
INTRODUCTION
It is quite precarious, when laser is directly
interfaced with the optical system ahead. When input
operating frequency of laser is increase above 1 GHz, the
power consumption is increased drastically. At 20 THz,
the power consumption is increased up to 98%. This
increase in power may destroy the attached device forever
(Belfiore, Szilagyi, Henker, and Ellinger, 2015)].
Laser driver works as interface between laser and
additional devices attached to laser. Laser output is very
sensitive at high frequency the power of device is
increasing drastically and this must be controlled to
protect other devices connected to laser using laser driver
(Capellini, Wenger, Schroder, and Kozlowski, 2015).
When laser frequency is exceeded the power and current
of the laser also increased. This increased power may
cause the permanent disability to the additional
components attached to the laser(Camilotti et al., 2015).
Laser driver provides the switching for laser to shield the
additional devices attached to laser. The efficient
designing of the laser driver only provides the switching
when laser output is out bound from ranges. Energy
efficient design of laser driver means with the switching it
must save the power when laser crosses outbound
operating ranges(Eimerl et al., 2014). There are various
techniques are available to control the output of power of
laser driver such as manually change the input voltage
source of laser, provides the bias circuit between laser and
additional components and etc. but none of them has
potential to provide energy efficient output (Kostamovaara
et al., 2015). This is because the laser driver circuit is not
saving the power and each time replacing the physical
components to produce the laser output is also costly and
time wasting and this process is not advisable
practically(K. Liu et al., 2014).
In this work above, mentioned problems are
encountered. This research provides the high frequency
switching between laser and additional devices and
consume less power when operating at high frequency.
Furthermore, the designed is realized using the System on
Chip (SoC) configuration on FPGA to avoid the
components replacement and saves times to produce the
different laser output(Lim, Kong, Kwon, and Lim, 2014).
The high frequency switching of 15 THz and between
laser and additional components is achieved. Additionally,
power consumption is reduced for different high operating
frequency of laser(Cundiff, Wahlstrand, Zhang, and Choi,
2014). The current stability and high frequency switching
is performed by designing the laser driver circuit for high
frequency laser using current mode logic technique. After
incorporating the CML based laser driver circuit in FPGA
using VLSI, the power consumption is reduced by
applying the voltage scaling technique. In FPGA, voltage
scaling is performed by changing the core voltage of
FPGA viretx-7(Kastensmidt et al., 2014). The complete
energy efficient design of laser driver is experimentally
demonstrated using FPGA Virtex-7.
LITERATURE REVIEW
Laser are widely used optical sources due to its
exceptional size, spectral region of procedure and high
efficiency (Gu et al., 2015) to transmit data over optical
fiber. Currently, high frequency operation at low power
consumption is in demand (Xu, Gu, Wu, and Chang,