Portable solar laser showers is a device that uses lasers powered by solar energy to stimulate plant growth in farmlands. The device combines red and blue laser beams and uses lenses to illuminate a wide area. Studies show crops irradiated for 30-60 seconds per day with this device experience 33% faster growth compared to sunlight alone. The solar-powered batteries can fully charge during the day, requiring no external power source. This portable design allows the benefits of laser stimulation to increase crop yields over large areas in an affordable and sustainable manner.

1. Portable Solar Laser Showers
Radhheya Sivarkar (1021310286)
radhheyasivarkar@gmail.com
Akshansh Mishra (1021310334)
akshanshmishra11@gmail.com
Dept. of Mechanical Engineering
SRM University
Kattankulathur, Chennai
Abstract-
With the ever growing population, the need is not
just the land under agriculture to rise, but also are
technologies to improve the quality and quantity
of the produce. With research showing that laser
exposure to crops is beneficial for both the
amount of produce with higher growth rates and
quality of yield is maintained. Portable solar laser
showers is an attempt to use renewable energy to
power lasers whose light would be used to radiate
crops in a farmland. Portability of the laser
shower apparatus would significantly increase the
area under laser illumination and hence making it
economical when used for the entire village or
district. The laser power source is solar powered
and hence rechargeable free and easily. Solar
panels charge the battery. Efficiency of solar
panels is increased using parabolic mirrors. Red
and blue laser beams are combined using Dichroic
Beam combiner and the output passed through a
combination of concave lenses to increase the area
under illuminance. Hence we believe Portable
solar laser showers can in the future be an aid for
increase in plant growth rates expected upto 40%,
hence help in reducing inflation and satisfy the
hunger of millions.
I. INTRODUCTION
Many researches have yielded the positive effect of
lasers on growth of plants. Laser treatment is a
physical phenomenon in which light energy is
absorbed by grains. It increases the energy potential
of seeds, which in turn impacts the physiological
processes in germinating seeds, thus accelerating
maturity, increasing resistance to disease as well as
raising the biological and processing quality of the
yield. In comparison with conventional light sources,
laser is distinguished by characteristics such as
mono-chromatism, polarization, coherence and high
density. Changes that occur in the physiological state
of an organism depend closely on the laser radiation
type, its wavelength, laser power, exposure time,
intensity, species and cultivar of the plants. It has
been shown that laser pretreatment could protect the
cells of a plant from drought stress damage with
enhancing the activity of many enzymes. Moreover,
proper laser pretreatment can accelerate physiological
and biochemical metabolism and accordingly
enhance the seedling growth.
Exposure of seedlings to monochromatic red light
(600-750 nm) stimulates seed germination and plant
growth since the first class of phytochromes,
responsible for light sensitive processes like growth,
are highly sensitive towards red light. Red light
irradiation also causes an increase in mineral contents
like Sodium, Zinc and Iron content.
Exposure of plants to monochromatic blue light
(320-500 nm) stimulates flowering and production.
Cryptochromes, that are blue light receptors in plants,
are necessary for photomorphogenesis and plant
growth. If we combine the exposures to red and blue
lights of the plant, we can maximize the yield, rate of
plant growth, which is the aim of Photonics.
In this paper, we present a pioneering method to
utilize the benefits of lasers in crop growth on a
commercial and large scale. Since the apparatus is
portable, it serves the purpose of the entire district or
village and hence making it economical when used
on a large scope.

2. II. APPARATUS AND OBSERVATIONS
Fig.1 Arrangement of the Portable Solar Laser Shower Apparatus
The apparatus consists of 2 laser sources of 15mW
power, one He-Ne (Helium-Neon) Red laser and the
other Ga-N (Gallium Nitride) Blue laser with
intensity of 40 mJ/sq.cm. The 2 laser beams are
combined using a Dichroic Beam Combiner with the
Red light component being of 90% illuminance and
Blue light component being 10% illuminance in the
combination spectrum. The output is passed through
a combination of concave lenses (L1 and L2) to
increase the area under irradiation of the farmland.
The laser irradiation on the plants should be given for
30-60 sec/day. Comparative studies on Laser
irradiated and Sunlight irradiated crop growth
comparison for Cereals like Wheat show that there is
33% faster growth in Laser irradiated crops.
If crops are irradiated for 30-60 sec/day after their
sunlight photoperiod, we can boost the growth rate of
the crops along with the following advantages:
- Laser exposure has shown plants to repair
their damaged tissues, due to Ultraviolet
Light component of sunlight, more rapidly.
- Laser power source, the battery is charged
by solar chargers that would be charged
during the plant photoperiod too. Hence no
external power source is needed to operate
the apparatus.
The above graphs clearly conclude that the
germination and root growth is optimum when
exposure to laser light is 30-40 seconds/day and the
stem growth is optimized with laser exposure for 30-
40 seconds/day with a laser of power 15mW.

3. III. SOLAR BATTERY RECHARGING
Fig.2 Arrangement for Solar Battery charging
The battery that powers the laser sources can be
charged using solar battery chargers. Solar battery
chargers are made up of a combination of solar cells,
diodes, transistor and capacitors. Parabolic mirrors
are configured around the solar panel to concentrate
maximum sunlight over the panel to increase the
temperature of the solar cells and hence to increase
the transduced electric charge to be stored in the
battery. Hence, renewable source of energy is
efficiently utilized to charge the battery that powers
the laser. Thus, no external energy is consumed to
increase the growth rate and maintain the quality of
the produce.
The practical efficiency of the charger is less than 10%.
The efficiency of the charging can be increased in the following ways:
- Using Polychromats on cells
- Single Fission
- Aluminium studs on solar panels
Fig.3 Solar battery charger circuit

4. IV. CONCLUSION
The laser radiations produced by a semiconductor
laser, with Red and Blue wavelengths, modify the
germination and velocity of growth of cereal seeds
when they are treated before sowing with the laser
radiation and during growth. The power density of
laser radiation and the exposition time for a definite
wavelength are the important parameters that can
activate or inhibit the germination and the velocity of
growth of wheat seeds. When the power density and
the exposition time to laser radiation are optimal it is
possible to improve the initial stages of growth of
crops (germination and growth). Single exposure of
laser is more effective than multiple exposures of
laser.
The Green Revolution resulted from science-led
appropriate technology requires the agriculture sector
to continually search and adopt more productive and
sustainable technologies. As a conclusion, Portable
Laser Showers should be made commercially viable
so that the stimulating effect of lasers can boost
growth rates of cereals and other food crops hence
which quantity of food grains would be higher, thus
fighting inflation and satisfying the hunger of
millions.
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