CHAPTER 1

INTRODUCTION

An ignition system is a system for igniting a fuel-air mixture. It is best known in

the field of internal combustion engines but also has other applications, e.g. in oil-fired

and gas-fired boilers. The earliest internal combustion engines used a flame, or a heated

tube, for ignition but these were quickly replaced by systems using an electric spark.

The power required for the motion of a vehicle is obtained by controlled

combustion of fuel/air mixture in the cylinder of the engine. The energy produced due to

this combustion is converted and transmitted from the engine to the wheels by means of

mechanical linkages. The process of combustion of fuel is initiated by the ignition

system.

The ignition system has two tasks to perform. First, it must create a voltage high

enough (20,000+) to arc across the gap of a spark plug, thus creating a spark strong

enough to ignite the air/fuel mixture for combustion. Second, it must control the timing

of that the spark so it occurs at the exact right time and send it to the correct cylinder.

In IC engines there are 2 types of ignition based on the fuel being used:

1. Spark ignition (petrol engine)

2. Compression ignition (diesel engine)

Economic as well as environmental constraints demand a further reduction in the fuel

consumption and the exhaust emissions of motor vehicles. At the moment, direct injected

fuel engines show the highest potential in reducing fuel consumption and exhaust

emissions. Unfortunately, conventional spark plug ignition shows a major disadvantage

with modern spray-guided combustion processes since the ignition location cannot be

chosen optimally. It is important that the spark plug electrodes are not hit by the injected

fuel because otherwise severe damage will occur. Additionally, the spark plug electrodes

can influence the gas flow inside the combustion chamber.

1

It is well know that short and intensive laser pulses are able to produce an “optical

breakdown” in air. Necessary intensities are in the range between 1010- 1011W/cm2. At

such intensities, gas molecules are dissociated and ionized within the vicinity of the focal

spot of a laser beam and a hot plasma is generated. This plasma is heated by the incoming

laser beam and a strong shock wave occurs. The expanding hot plasma can be used for

the ignition of fuel-gas mixtures.

2

CHAPTER 2

CONVENTIONAL SPARK IGNITION

In a petrol engine, the fuel and air are usually pre-mixed before compression. The pre-

mixing was formerly done in a carburettor, but now (except in the smallest engines) it is

done by electronically controlled fuel injection.

In this system fuel entering the engine cylinder is ignited by means of a spark. The

required amount of fuel is induced into the cylinder during suction stroke. This fuel is

ignited during the compression stroke by a spark produced by a spark plug. Due to the

combustion of fuel large amount of heat and high pressure gases are produced which

expand causing linear motion of the piston.

Based on the method by which spark is created and distributed, ignition systems are

classified as:

1. Mechanical ignition System

2. Electronic ignition system

3. Distributor less ignition system

3

2.1 DRAWBACKS OF CONVENTIONAL SPARK IGNITION

Location of spark plug is not flexible as it require shielding of plug from

immense heat and fuel spray.

It is not possible to ignite inside the fuel spray.

It requires frequent maintenance to remove carbon deposits.

Leaner mixtures cannot be burned.

Degradation of electrodes at high pressure and temperature.

Flame propagation is slow.

Multi point fuel ignition is not feasible.

Higher turbulence levels are required.

Economic as well as environmental considerations compel to overcome above

disadvantages and use a better system.

All the above drawbacks are overcome in laser ignition system explained as follows.

4

CHAPTER 3

LASER

Lasers provide intense and unidirectional beam of light. Laser light is

monochromatic (one specific wavelength). Wavelength of light is determined by amount

of energy released when electron drops to lower orbit. Light is coherent; all the photons

have same wave fronts that launch to unison. Laser light has tight beam and is strong and

concentrated. To make these three properties occur takes something called “Stimulated

Emission”, in which photon emission is organized. The term "laser" is an acronym for

Light Amplification by Stimulated Emission of Radiation.

Main parts of laser are power supply, lasing medium and a pair of precisely aligned

mirrors. One has totally reflective surface and other is partially reflective (96 %). The

most important part of laser apparatus is laser crystal. Most commonly used laser crystal

is manmade ruby consisting of aluminium oxide and 0.05% chromium. Crystal rods are

round and end surfaces are made reflective. A laser rod for 3 J is 6 mm in diameter and

70 mm in length approximately. Laser rod is excited by xenon filled lamp, which

surrounds it. Both are enclosed in highly reflective cylinder, which directs light from

flash lamp in to the rod. Chromium atoms are excited to higher energy levels. The excited

ions meet photons when they return to normal state. Thus very high energy is obtained in

short pulses. Ruby rod becomes less efficient at higher temperatures, so it is continuously

cooled with water, air or liquid nitrogen. The Ruby rod is the lasing medium and flash

tube pumps it.

Fig. 3.1 Laser in its non lasing state.

5

Fig. 3.2 The flash tube fires and injects light into the ruby rod. The light excites atoms

in the ruby.

Fig. 3.3 Some of these atoms emit photons.

Fig. 3.4 Photons run in a directional ruby axis, so they bounce back and forth off the

mirrors. As they pass through the crystal, they stimulate emission in other atoms.

6

Fig. 3.5 Monochromatic, single phase columnated light leaves the ruby through the half

silvered mirror laser light.

3.1 PROPERTIES OF LASER LIGHT

1. Monochromatic: Photons of one wavelength. In contrast, ordinary white light is a

combination of different wavelengths.

2. Directional: Laser light is emitted as a narrow beam and in a specific direction. This

property is referred to as directionality.

3. Coherent: The light from a laser is said to be coherent. This means that the

wavelengths of the laser light are in phase.

3.2 LASERS AND THEIR EMISSION WAVELENGTHS

Laser Type  Wavelength (nm) 

Argon fluoride (UV)  193 

Krypton fluoride (UV)  248 

Xenon chloride (UV)  308 

Nitrogen (UV)  337 

Argon (blue)  488 

Argon (green)  514 

Helium neon (green)  543 

Helium neon (red)  633 

Rhodamine 6G dye (tunable)  570-650 

Ruby (CrAlO3) (red)  694 

Nd:Yag (NIR)  1064 

7

Carbon dioxide (FIR)  10600 

3.3 TYPES OF LASERS

3.3.1 GAS LASERS

The Helium-neon laser (HeNe) emits 543 nm and 633 nm and is very common in

education because of its low cost. Carbon dioxide lasers emit up to 100 kW at 9.6 µm and

10.6 µm, and are used in industry for cutting and welding. Argon-Ion lasers emit 458 nm,

488 nm or 514.5 nm. Carbon monoxide lasers must be cooled but can produce up to 500

kW. The Transverse Electrical discharge in gas at Atmospheric pressure (TEA) laser is an

inexpensive gas laser producing UV Light at 337.1 nm.

Metal ion lasers are gas lasers that generate deep ultraviolet wavelengths. Helium-

Silver (HeAg) 224 nm and Neon-Copper (NeCu) 248 nm are two examples. These lasers

have particularly narrow oscillation line widths of less than 3 GHz (0.5 picometers)

making them candidates for use in fluorescence suppressed Raman spectroscopy.

3.3.2 CHEMICAL LASERS

Chemical lasers are powered by a chemical reaction, and can achieve high powers

in continuous operation. For example, in the Hydrogen fluoride laser (2700-2900 nm) and

the Deuterium fluoride laser (3800 nm) the reaction is the combination of hydrogen or

deuterium gas with combustion products of ethylene in nitrogen trifluoride.

3.3.3 EXCIMER LASERS

Excimer lasers produce ultraviolet light, and are used in semiconductor

manufacturing and in LASIK eye surgery. Commonly used excimer molecules include F2

(emitting at 157 nm), ArF (193 nm), KrCl (222 nm), KrF (248 nm), XeCl (308 nm), and

XeF (351 nm).

3.3.4 SOLID-STATE LASERS

Solid state laser materials are commonly made by doping a crystalline solid host

with ions that provide the required energy states. For example, the first working laser was

made from ruby, or chromium-doped sapphire. Another common type is made from

8

Neodymium-doped yttrium aluminium garnet (YAG), known as Nd:YAG. Nd:YAG

lasers can produce high powers in the infrared spectrum at 1064 nm. They are used for

cutting, welding and marking of metals and other materials, and also in spectroscopy and

for pumping dye lasers. Nd:YAG lasers are also commonly doubled their frequency to

produce 532 nm when a visible (green) coherent source is required.

Ytterbium, holmium, thulium and erbium are other common dopants in solid state

lasers. Ytterbium is used in crystals such as Yb:YAG, Yb:KGW, Yb:KYW, Yb:SYS,

Yb:BOYS, Yb:CaF2, typically operating around 1020-1050 nm. They are potentially very

efficient and high powered due to a small quantum defect. Extremely high powers in

ultrashort pulses can be achieved with Yb:YAG. Holmium-doped YAG crystals emit at

2097 nm and form an efficient laser operating at infrared wavelengths strongly absorbed

by water-bearing tissues. The Ho-YAG is usually operated in a pulsed mode, and passed

through optical fiber surgical devices to resurface joints, remove rot from teeth, vaporize

cancers, and pulverize kidney and gall stones. Titanium-doped sapphire (Ti:sapphire)

produces a highly tunable infrared laser, used for spectroscopy.

Solid state lasers also include glass or optical fiber hosted lasers, for example,

with erbium or ytterbium ions as the active species. These allow extremely long gain

regions, and can support very high output powers because the fiber's high surface area to

volume ratio allows efficient cooling and its wave guiding properties reduce thermal

distortion of the beam.

3.3.5 SEMICONDUCTOR LASERS

Laser diodes produce wavelengths from 405 nm to 1550 nm. Low power laser diodes are

used in laser pointers, laser printers, and CD/DVD players. More powerful laser diodes

are frequently used to optically pump other lasers with high efficiency. The highest power

industrial laser diodes, with power up to 10 kW, are used in industry for cutting and

welding. External-cavity semiconductor lasers have a semiconductor active medium in a

larger cavity. These devices can generate high power outputs with good beam quality,

wavelength-tuneable narrow-line width radiation, or ultra-short laser pulses.

Vertical cavity surface-emitting lasers (VCSELs) are semiconductor lasers whose

emission direction is perpendicular to the surface of the wafer. VCSEL devices typically

have a more circular output beam than conventional laser diodes, and potentially could be

much cheaper to manufacture. As of 2005, only 850 nm VCSELs are widely available,

9

with 1300 nm VCSELs beginning to be commercialized, and 1550 nm devices an area of

research. VECSELs are external-cavity VCSELs. Quantum cascade lasers are

semiconductor lasers that have an active transition between energy sub-bands of an

electron in a structure containing several quantum wells.

3.3.6 DYE LASERS

Dye lasers use an organic dye as the gain medium. The wide gain spectrum of

available dyes allows these lasers to be highly tunable, or to produce very short-duration

pulses (on the order of a few femtoseconds).

10

CHAPTER 4

LASER IGNITION SYSTEM IN SI ENGINES

The use of laser ignition to improve gas engine performance was initially

demonstrated by J. D. Dale in 1978. However, with very few exceptions, work in this

area has for the last 20 years been limited to laboratory experimentation employing large,

expensive and relatively complicated lasers and laser beam delivery systems. More

recently, researchers at GE-Jenbacher, Mitsubishi Heavy Industries, Toyota, National

Energy Technology Lab and Argonne National Lab have obtained and/or built smaller

high peak power laser spark plugs.

Unlike many earlier laboratory laser systems, these smaller lasers are now

mounted directly onto the engine cylinder head so as to fire the laser beam directly into

the chamber. This arrangement allows the laser to become a direct replacement for the

traditional high voltage electrical spark-gap plug. Further reductions in laser size, price

and complexity will help the laser spark plug become a commercial reality and a viable

competitor to the traditional high voltage spark-gap plug.

4.1 INTRODUCTION

The process begins with multi-photon ionization of few gas molecules which

releases electrons that readily absorb more photons via the inverse bremsstrahlung

process to increase their kinetic energy. Electrons liberated by this means collide with

other molecules and ionize them, leading to an electron avalanche, and breakdown of the

gas. Multi photon absorption processes are usually essential for the initial stage of

breakdown because the available photon energy at visible and near IR wavelengths is

much smaller than the ionization energy. For very short pulse duration (few picoseconds)

the multiphoton processes alone must provide breakdown, since there is insufficient time

for electron-molecule collision to occur. Thus this avalanche of electrons and resultant

ions collide with each other producing immense heat hence creating plasma which is

sufficiently strong to ignite the fuel. The wavelength of laser depend upon the absorption

11

properties of the laser and the minimum energy required depends upon the number of

photons required for producing the electron avalanche.

(a) 1064 nm. (b) 532 nm.

Fig. 4.1 Optical breakdown in air generated by a Nd:YAG laser.

4.2 WORKING

The laser beam is passed through a convex lens, this convex lens diverge the beam

and make it immensely strong and sufficient enough to start combustion at that point.

Hence the fuel is ignited, at the focal point, with the mechanism shown above. The focal

point is adjusted where the ignition is required to have.

Convex lens

12

Laser beam

Focused laser

Plasma I>Ithreshold

E>Eignition

Mixture burning

Fig. 4.2 Working of Laser Ignition System

4.3 PARTS OF LASER IGNITION SYSTEM

A laser ignition device for irradiating and condensing laser beams in a combustion

chamber of an internal combustion engine so as to ignite fuel particles within the

combustion chamber, includes: a laser beam generating unit for emitting the laser beams;

and a condensing optical member for guiding the laser beams into the combustion

chamber such that the laser beams are condensed in the combustion chamber.

Fig. 4.3 Laser Arrangement with Respect to Engine

4.3.1 POWER SOURCE

The average power requirements for a laser spark plug are relatively modest. A

four stroke engine operating at maximum of 1200 rpm requires an ignition spark 10 times

per second or 10Hz (1200rpm/2x60). For example 1-Joule/pulse electrical diode pumping

levels we are readily able to generate high millijoule levels of Q-switched energy. This

provides us with an average power requirement for the laser spark plug of say

approximately 1-Joule times 10Hz equal to approximately 10 Watts.

13

4.3.2 Nd:YAG LASER

It is the most suitable laser beam generating unit in laser ignition system.

Nd:YAG (neodymium-doped yttrium aluminium garnet; Nd:Y3Al5O12) is a crystal that is

used as a lasing medium for solid-state lasers. The dopant, triply ionized neodymium,

typically replaces yttrium in the crystal structure of the yttrium aluminium garnet (YAG),

since they are of similar size. Generally the crystalline host is doped with around 1%

neodymium by atomic percent. They typically emit light with a wavelength of 1064 nm,

in the infrared. However, there are also transitions near 940, 1120, 1320, and 1440 nm.

Nd:YAG lasers operate in both pulsed and continuous mode. Pulsed Nd:YAG lasers are

typically operated in the so called Q-switching mode: An optical switch is inserted in the

laser cavity waiting for a maximum population inversion in the neodymium ions before it

opens. Then the light wave can run through the cavity, depopulating the excited laser

medium at maximum population inversion.

4.3.3 COMBUSTION CHAMBER WINDOW

Since the laser ignition system is located outside the combustion chamber a

window is required to optically couple the laser beam. The window must:

Withstand the thermal and mechanical stresses from the engine.

Withstand the high laser power.

Exhibit low propensity to fouling.

4.3.4 OPTIC FIBER WIRE

It is used to transport the laser beam from generating unit to the focusing unit.

4.3.5 FOCUSING UNIT

A set of optical lenses are used to focus the laser beam into the combustion

chamber. The focal length of the lenses can be varied according to where ignition is

required. The lenses used may be either combined or separated.

14

Fig. 4.4 Focusing Optics

4.4 MULTIPOINT IGNITION

Laser ignition system can also be used for multipoint ignition in engines. The

laser beam generated will be divided 2 or more beams by means of diffraction grating.

Each beam is directed by optic fiber and focused into their respective laser spark plugs.

Fig. 4.5 Approach for Multipoint Ignition

15

4.5 MINIMUM ENERGY REQUIRED FOR IGNITION

The minimum ignition energy required for laser ignition is more than that for

electric spark ignition because of following reasons:

An initial comparison is useful for establishing the model requirements, and for

identifying causes of the higher laser MIE. First, the volume of a typical electrical

ignition spark is 103 cm3. The focal volume for a typical laser spark is 10-5 cm3. Since

atmospheric air contains _1000 charged particles/cm3, the probability of finding a charged

particle in the discharge volume is very low for a laser spark.

Second, an electrical discharge is part of an external circuit that controls the

power input, which may last milliseconds, although high power input to ignition sparks is

usually designed to last < 100 ns. Breakdown and heating of laser sparks depend only on

the gas, optical, and laser parameters, while the energy balance of spark discharges

depends on the circuit, gas, and electrode characteristics. The efficiency of energy

transfer to near-threshold laser sparks is substantially lower than to electrical sparks, so

more power is required to heat laser sparks. Another reason is that, energy in the form of

photons is wasted before the beam reach the focal point. Hence heating and ionizing the

charge present in the path of laser beam. This can also be seen from the propagation of

flame which propagates longitudinally along the laser beam. Hence this loss of photons is

another reason for higher minimum energy required for laser ignition than that for electric

spark.

4.6 ADVANTAGES OF LASER INDUCED SPARK IGNITION

Location of spark plug is flexible as it does not require shielding from immense

heat and fuel spray and focal point can be made anywhere in the combustion chamber

from any point. It is possible to ignite inside the fuel spray as there is no physical

component at ignition location.

It does not require maintenance to remove carbon deposits because of its self-

cleaning property.

High pressure and temperature does not affect the performance allowing the use

of high compression ratios.

Flame propagation is fast as multipoint fuel ignition is also possible.

Higher turbulence levels are not required due to above said advantages.

16

A choice of arbitrary positioning of the ignition plasma in the combustion

cylinder.

Absence of quenching effects by the spark plug electrodes.

Ignition of leaner mixtures than with the spark plug => lower combustion

temperatures => less NOx emissions.

No erosion effects as in the case of the spark plugs => lifetime of a laser ignition

system expected to be significantly longer than that of a spark plug.

High load/ignition pressures possible => increase in efficiency.

Precise ignition timing possible.

Exact regulation of the ignition energy deposited in the ignition plasma.

Easier possibility of multipoint ignition.

Shorter ignition delay time and shorter combustion time.

Fuel-lean ignition possible.

4.7 FLAME PROPAGATION IN COMBUSTION CHAMBER

Fig.4.6 Flame propagation.

17

CHAPTER 5

COMBUSTION CHAMBER EXPERIMENT

Performed by, Institute for Internal Combustion Engines and Automotive

Engineering, Vienna

5.1. INTRODUCTION

As a feasibility test, an excimer laser has been used for ignition of inflammable

gases inside a combustion bomb. The laser used for the first experiments was a Lambda

Physik LPX205, equipped with an unstable resonator system and operated with KrF,

delivering pulses with a wavelength of 248 nm and a duration of approximately 34 ns

with maximum pulse energy of 400 mJ.10 The combustion chamber has had a diameter

of 65 mm and a height of 86mm, with a resulting volume of 290cm3 and was made of

steel. The laser beam was guided into the chamber through a window. Pressure sensors,

filling and exhaust lines were also connected to the combustion chamber. The laser beam

was focused into the chamber by means of a lens with a focal length of 50 mm.

Variations of pulse energies as well as gas mixtures have been performed to judge the

feasibility of the process. Results indicate that ignition-delay times are smaller and

pressure gradients are much steeper compared to conventional spark plug ignition.

5.2. ENGINE EXPERIMENTS

Since the first feasibility experiments could be concluded successfully, an engine was

modified for laser ignition. The engine has been modified by a replacement of the

conventional spark plug by a window installed into a cylindrical mount. The position of

the focusing lens inside the mount can be changed to allow variations of the location of

the initial optical breakdown. First experiment with laser ignition of the engine have been

performed with an excimer laser, later a q-switched Nd:YAG has been used, see table 5.1.

18

Fig.5.1 Research engine with the q-switched Nd:YAG laser system.

The replacement of the excimer laser was mainly caused by the fact that especially at

very low pulse energies the excimer laser shows strong energy fluctuations. Pressure

within the combustion chamber has been recorded as well as fuel consumption and

exhaust gases. The laser was triggered at well defined positions of the crankshaft, just as

with conventional ignition systems. Pulse energies, ignition location and fuel/air ratios

have been varied during the experiments. The engine has been operated at each setting for

several hours, repeatedly. All laser ignition experiments have been accompanied by

conventional spark plug ignition as reference measurements.

19

Table 5.1 Technical data of the research engine and the Nd:YAG laser used for the

experiments.

Research engine Q-switched Nd:YAG

No. of cylinders 1 Pump source Flash lamp

No. of valves 1 Wavelength 1064 or 532 nm

Injector Multi-hole Max. pulse energy 160 mJ

Stroke 85 mm Pulse duration 6 ns

Bore 88 mm Power consumption 1 kW

Displacement vol. 517 cm 3 Beam diameter 6 mm

Compression ratio 11.6 Type Quantel Brilliant

5.3 RESULTS OF EXPERIMENT

Results of the experiments are summarized in fig.5.2. Fig.5.2. shows that laser

ignition has advantages compared to conventional spark plug ignition. Compared to

conventional spark plug ignition, laser ignition reduces the fuel consumption by several

per cents. Exhaust emissions are reduced by nearly 20%. It is important that the benefits

from laser ignition can be achieved at almost the same engine smoothness level, as can be

seen from fig.5.2. Additionally, a frequency-doubled Nd:YAG laser has been used to

examine possible influences of the wavelength on the laser ignition process. No

influences could be found. Best results in terms of fuel consumption as well as exhaust

gases have been achieved by laser ignition within the fuel spray. As already mentioned, it

is not possible to use conventional spark plugs within the fuel spray since they will be

destroyed very rapidly. Laser ignition doesn’t suffer from that restriction.

20

Con-sumption

Smoothness Emissions80

90

100

110

Spark ignition between fuel sprayLaser ignition between fuel sprayLaser ignition within fuel spray

(Perc

en

t)

Fig.5.2 Result comparison

Another important question with a laser ignition system is its reliability. It is clear

that the operation of an engine causes very strong pollution within the combustion

chamber. Deposits caused by the combustion process can contaminate the beam entrance

window and the laser ignition system will probably fail. To quantify the influence of

deposits on the laser ignition system, the engine has been operated with a spark plug at

different load points for more than 20 hours with an installed beam entrance window. As

can be seen in fig., the window was soiled with a dark layer of combustion deposits.

Afterwards, a cold start of the engine was simulated. Already the first laser pulse ignited

the fuel/air mixture. Following laser pulses ignited the engine without misfiring, too.

After 100 cycles the engine was stopped and the window was disassembled. As can be

seen from fig, all deposits have been removed by the laser beam. Additional experiments

showed that for smooth operation of the engine the minimum pulse energy of the laser is

determined by the necessary intensity for cleaning of the beam entrance window.

Estimated minimum pulse energies are too low since such “self-cleaning” mechanisms

are not taken into account. Engine operation without misfiring was always possible above

a certain threshold intensity at the beam entrance window. For safe operation of an engine

even at cold start conditions an increased pulse energy of the first few laser pulses would

be beneficial for cleaning of the beam entrance window.

21

Fig.5.3 Self-cleaning of Beam entrance window

1. After 20 h operation with spark plug ignition, heavily polluted

2. Immediately after 100 laser pulses. Beam area is cleaned by the laser beam.

5.3.1 COMPARISON OF LASER IGNITION – SPARK PLUG IGNITION WITH

RESPECT TO RELIABILITY

From the graph of ignition pressure vs. air-fuel ratio it can be seen that 100%

reliability can be achieved in laser ignition at a higher air-fuel ratio of 2.05, than in spark

ignition. Hence leaner mixture can be used in laser ignition system to achieve 100%

reliability.

For 100% ignition reliability at 30 bar

A/Frel = 2.05 (laser ignition)

A/Frel = 1.74 (spark ignition)

22

5.3.2 COMPARISON OF NOx EMISSION POTENTIALS OF VARIOUS IGNITION

METHODS

The graph below shows NOx emission levels in different ignition systems. It can

be seen that NOx emissions are considerably lesser in case of laser ignition system. This

is due to the fact that lean air-fuel mixtures can be burnt easily in laser ignition systems,

leading to lower combustion chamber temperatures and hence lower NOx emissions.

NOX in [mg/Nm³]

Direct Pre chamber Direct Pre chamber

Spark ignition Laser ignition Diesel pilot ignition

23

0

50

100

150

200

250

300

350

250

190

70

330

240

CHAPTER 6

CONCLUSION

The applicability of a laser-induced ignition system on direct injected gasoline

engine has been proven. Main advantages are the almost free choice of the

ignition location within the combustion chamber, even inside the fuel spray.

Significant reductions in fuel consumption as well as reductions of exhaust gases

show the potential of the laser ignition process.

At present, a laser ignition plug is very expensive compared to a standard

electrical spark plug ignition system and it is nowhere near ready for deployment.

But potential advantages will surely bring it in to market for many practical

applications.

24

REFERENCES

1. “Laser Ignition in Internal Combustion Engines”, Pankaj Hatwar, Durgesh Verma;

International Journal of Modern Engineering Research (IJMER),Vol.2, Issue.2, Mar-Apr

2012 pp-341-345.

2. "Laser Plasma-Initiated Ignition of Engines", J. Tauer1, H. Kofler, K. Iskra, G.

Tartar And E. Wintner; 3rd International Conference on the Frontiers of Plasma Physics

and Technology

3. "Laser Ignition - a New Concept to Use and Increase the Potentials of Gas

Engines", Dr. Günther Herdin, DI Johann Klausner, Prof. Ernst Wintner; ASME Internal

Combustion Engine Division 2005 Fall Technical Conference, Ottawa, Canada.

4. http://www.iitk.ac.in/erl/laserignition.html

5. http://www.faqs.org/patents/app/20080264371

6. http://en.wikipedia.org/wiki/Ignition_system

7. http://auto.howstuffworks.com/ignition-system4.html

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