Photonic band gap (PBG) materials are artificially created materials that prevent the propagation of electromagnetic waves within a forbidden bandgap. PBG materials find various applications including EMI shielding, miniaturization of photonic devices, and magnetic field sensing. Photonic crystal fibers use the bandgap effect to guide light and have uses in telecommunications, sensing, and medicine.

1. PHOTONIC BAND GAP MATERIAL AND ITS
APPLICATION FOR EMI AND EMC

2. CONTENTS
Introduction
Types of Photonic band gap material Natura,Artificial l and types
Electromagnetic wave propagation in PBG material and Photonic Band gap
PCF and PC devices and its electro magnetic compatibility
PBG material in mitigation of EMI
EMC of PBG material
Summary
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3. INTRODUCTION
 Photonic band-gap (PBGs) materials are artificially created dielectric materials which prevents propagation of
electromagnetic waves that propagates through them. if they fall within the bandgap of
 that material,
 Photonic band gap: Range of forbidden frequencies within which a specific wavelength is blocked light is reflected
rather than transmitted.
 If a defect is created in these crystals will guide electromagnetic waves of certain frequency if it falls within the
band gap.
 The trend of miniaturizing the optical integrated devices has been boosted by the concept of photonic band
gap (PBG) material discovered by Yabolonvitch in 1989.
 Other band gap materials are sonic crystals which controls acoustic waves
 Metallo –Dielectric structures for absorption of electromagnetic waves
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4. EXAMPLES:NATURAL PHOTONIC
CRYSTAL (OPAL) AND BUTTERFLY
4

5. PEACOCK FEATHER(NATURAL PC)
5

6. SONIC
CRYSTALS
CONTROLS THE
ACOUSTIC
WAVE
6
Sonic crystal have a band gap for certain acoustic waves This
property is used in many applications such as sound barrier,
frequency filter, acoustic imaging etc.

7. PERIODIC METTALO DIELECTRIC STRUCTURE
TOP LAYER
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8. PERIODIC METTALO DIELECTRIC STRUCTURE
TOP LAYER
 In these bi-layer screens, the top (front) screen is
made of metallic hole-array and the bottom (back)
screen is made of metallic disk-array.
 The gap between them is filled with an array of
dielectric spheres. The spheres are embedded in a
dielectric host material.
 It is made of either a heat-insulating (air, polyimide)
or heat-conducting (MgO) layer.
 Electromagnetici ntensity trapping of 97% is
obtained when a 0.15 micron gap is filled with MgO
and Si spheres,
 Applications:anti-fogging surfaces, electromagnetic
shields, and energy harvesting structure
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9. APPLICATIONS
ALL ACTIVE AND
PASSIVE
PHOTONIC
DEVICES AND
EMI MITIGATION
& EMC
COMPATIBILITY
DEVICES
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Photonic Crystal Types

10. 2D PBG PHOTONIC CRYSTAL
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Fig. c) TE band structure for PC with air holes in
dielectric background d) TM band structure for PC
with rods in air
© (d)
Fig. a)PC with periodic airholes in dielectric background
b)PC with Dieleciric cylinders in air.

11. BANDGAP
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12. DEFECTS IN
PBG MATERIAL
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Creating a point defect: Increase/decrease the size of the air
holes ( PC with air holes)
Creating line defect:Removal of all the holes in a line(PC with air
holes)
Creating a point defect : enlarging the size of the rod/reducing the
size(PC with rods in dielectric background)
Line defect: Removal of row of rods (PC with rods in air)

13. SOME PC BASED DEVICES ( BENT WAVE GUIDE)
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14. 14

15. BLOCH THEOREM(SIMPLIFIED)
 When the electromagnetic wave propagates in a periodic structure is considered we use Bloch theorem
 Essentially it is a translation operator that commutes with Hamiltonian
 Hamiltonian of a system is an operator corresponding to the total energy of that system, including both
kinetic energy and ...
 Hamiltonian operator extracts the eigen value of the energy as a function of crystal momentum.
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16. PBG MATERIAL FOR
EMI MITIGATION
Photonic Bandgap (PBG) shielding technology is a new
approach to designing electromagnetic shielding
materials for mitigating Electromagnetic Interference
(EMI) with small, light-weight shielding materials.
Surface currents over some frequency ranges behave as
if on a standard conductive metallic ground plane,
providing no attenuation to microstrip or co-planar
waveguide transmission lines.
If the interfering frequency falls within the bandgap of
the PBG ground it is blocked or scattered or attenuated.
NASA used this PBG shielding for constellation for to and
fro Mars travel by human visitors.
Polyimides and metalic conducting polymers and PCs
are used.
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17. PBG STRUCTURE ON
SURFACE OF A MISSILE
AND SPACECRAFT
 Patch antenna are often designed on the
missile and space craft.
 They couple power of the order of 3dB to
the metallic skin next to the patch
antenna.
 Using a ring of PBG material around the
patch antenna will reduce the power loss.
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18. APPLICATION OF
PHOTONIC CRYSTALS
IN SUB-TERAHERTZ-
WAVE SWITCH
 The subterahertz and terahertz frequency ranges are promising for the
creation of high-speed wireless communication systems because of
the possibility to achieve a bandwidth of about several dozen
gigahertz, which ensures a high channel capacity.
 2D dielectric silicon PC with diameter of the holes 0.4a and Refractive
index is 3.4
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19. PHOTONIC CRYSTAL FIBER
 Photonic crystal fiber is a
microstructure fiber endlessly single
mode.It can guide light by two
methods 1) total internal reflection
like the conventional fiber.
 It can also guide light using a hollow
core structure. These type of fiber
guide light by PBG effect and are
known as hollow core fibers
 They have extensive applications in
Telecommunication engineering,
electronics,mechanical,biomedical
and civil engineering.
 These fibers are also known as band
gap material
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a) Solid core PCF b)Hollow core PCF

20. PHOTONIC CRYSTAL FIBER ( MAGNETIC FIELD SENSOR)
 A sandwich structure in dual core PCF is created for the detection of magnetic field.
 This acts as a magnetic sensor although PCF is a dielectric and made up of silica
 Broadband light is propagated through the two cores adject to each other.
 Void space between the two adjacent cores are filled with magnetic fluid
 Even and odd super modes with different propagation constant are formed which results in the super mode
interference
 Depending upon the magnetic field the effective RI of the magnetic fluid varies.
 MF under different magnetic field, and the magnetic field is measured by interrogating the wavelength shift of the
transmission spectrum.
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21. PHOTONIC CRYSTAL FIBER ( MAGNETIC FIELD SENSOR)
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22. SUMMARY
 PBG technogy can provide miniaturization resulting in light weight which is essential in space craft,radomes etc..
Where the payload counts.
 It reduces the cross talk between anolog and digital RF ciruits.
 Cost effective
 Finds application in biomedical engineering and biomedical instrumentation
 EMI shielding using PBG is gaining popularity. Essentaillay it enhances the effective isotropic radiated power
 .
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23. REFERENCES
 [1] E. Yablonovitch J. Opt. Soc. Am. B/Vol. 10, No. 2/February 1993
 [2] Biswas R., Chan C.T., Sigalas M., Soukous's C.M., Ho K.M. (1996) Photonic Band Gap Materials. In: Soukoulis C.M. (eds) Photonic Band
Gap Materials. NATO ASI Series (Series E: Applied Sciences), vol 315. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-1665-4_
 [3] Li Jiusheng l'2, Du Tieying 2,” Application of Photonic Crystals in sub-terahertz-wave Switch”
 [4] Xiaoqiuyan Zhang, Min Hu, Sen Gong, Zhenhua Wu, Yueheng Cao, Pengfei Hu and Shenggang Liu “
 Theoretical Calculation and Electromagnetic Simulation of Smith-Purcell in Photonic Crystals,2018.
 [5] Hong Wu1 * and Feng Li2,3 “ Negative-refraction Effect for Both TE and TM Polarizations in Two-dimensional Annular Photonic Crystals
“2018.
 [6] Dr. Gary L. Bastin, ASRC Aerospace “2007 Space and Missile Défense Conference, Huntsville, AL. 13-16 August 2007
 [7] Philip St.J. Russell volume “ Photonic crystal fiber” 24.Issue 12.pp 4729-4749,2006
 [8] Jean Paul Walker 1 , Venkataraman Swaminathan 2,† , Aisha S. Haynes 2 and Haim Grebel 1,* Periodic Metallo-Dielectric Structures:
Electromagnetic Absorption and its Related Developed Temperatures, 2019
 [9] Li Jiusheng, Du Tieying, “ Application of Photonic crystal in sub terahertz range” IEEE 2007 International Symposium on Microwave,
Antenna, Propagation, and EMC Technologies For Wireless Communications.
 [10] Ran Gao, Yi Jiang, and Gang Li” A Sandwich Structure for the Magnetic Field Detection With Supe rmodes Interference” EEE
PHOTONICS TECHNOLOGY LETTERS, VOL. 27, NO. 5, MARCH 1, 2015
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