The document presents an overview of terahertz (THz) electromagnetic waves, detailing their properties, history, and various applications in fields such as medicine and wireless communication. Terahertz radiation, which lies between microwaves and infrared frequencies, is non-ionizing and can penetrate various materials, making it valuable for imaging and security purposes. Despite current challenges in generation and detection, ongoing research aims to enhance THz applications, particularly in medical diagnostics.

1. Tera Hertz
Electromagnetic Waves
Presented By: Zeeshan Ahmed Lodro
B.E-VIII [ECE]
CmS ID#033-14-0062
Wireless And Mobile Communication
Department Of Electrical Engineering
Sukkur IBA University
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2. Agenda
Introduction to Tera Hertz.
History of Tera Hertz
Properties of Tera Hertz.
Applications of Tera Hertz.
Tera Hertz Generation and Detection
Tera Hertz in Wireless Communication.
Challenges
Solutions
Conclusion
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3. Introduction
Various frequencies are spaced along the frequently used electromagnetic spectrum
microwaves,
infrared radiations,
visible lights,
X-rays.
Between the microwave and infrared frequencies lies terahertz (THz) radiation.
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4. Introduction
Terahertz radiation – also known as submillimeter radiation
Terahertz waves, tremendously high frequency – consists of electromagnetic waves within
the ITU-designated band of frequencies from 0.3 to 3 terahertz (THz; 1 THz = 1012 Hz).
Wavelengths of radiation in the terahertz band correspondingly range from 1 mm to
0.1 mm
Photon energy in the THz region is less than the band-gap energy of non-metallic materials
and thus THz radiation can penetrate such materials.
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5. Introduction
THz beams transmitted through materials can be used for
Material characterization,
Layer inspection
It is an alternative to X-rays for producing high resolution images of the interior of solid
objects.
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6. Introduction
if we take generally Radiation at 1 THz has
 period of 1 ps,
 wavelength of 300 μm,
wave number of 33 cm–1
photon energy of 4.1 meV,
Equivalent temperature of 47.6 K.
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7. ・Frequency: 1THz=1012Hz
・Wavelength: 1THz 300µm
103 106 109 10181012 1015
killo mega giga tera peta exa
1021
zetta
THz region:0.1~10THz
Visible X-ray γ-rayMicrowaves
Frequency(Hz)
Example Radio Radar Optical Medical Astrophysics
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8. History
It has been several decades since electromagnetic radiation in the THz band was
first scientifically studied.
In the beginning, such radiation was called far-infrared waves or millimeter/submillimeter
waves.
It was through the development of ultrafast optoelectronics, which led to the successful
generation and detection of THz pulses in the middle 1980s, that interest in this particular
electromagnetic wave widely bloomed.
Early researchers were focused on developing technologies in generating, detecting, and
manipulating THz waves.
This was followed by utilizing THz waves in fundamental research. Lately, interest has
become more focused on the real-world application of THz waves.
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9. Properties
Terahertz radiation travels in a line of sight
 It is non-ionizing.
Like microwave radiation, terahertz radiation can penetrate a wide variety of non-conducting
materials.
Terahertz radiation can pass through
clothing,
 paper,
cardboard,
wood,
plastic and ceramics.
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10. Properties
The penetration depth is typically less than that of microwave radiation.
Terahertz radiation has limited penetration through fog and clouds and cannot penetrate
liquid water or metal.
 THz is not ionizing yet can penetrate some distance through body tissue, so it is of interest
as a replacement for medical X-rays.
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11. Properties
Being electromagnetic waves, the properties and behavior of THz waves are governed by
the Maxwell equations, just like the other waves.
However, due to their specific location on the electromagnetic spectrum, THz waves are
much more difficult to handle than waves adjacent to them.
THz waves have low photon energies and thus cannot lead to photoionization in biological
tissues as can X-rays.
 As a result, THz waves are considered safe for both the samples and the operator
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12. Properties
The earth's atmosphere is a strong absorber of terahertz radiation, so the range of
terahertz radiation in air is limited to tens of meters, making it unsuitable for long-distance
communications.
However, at distances of ~10 meters the band may still allow many useful applications in
imaging and construction of high bandwidth wireless networking systems, especially indoor
systems.
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13. Properties
Due to extreme water absorption, THz waves cannot penetrate into the human body like
microwaves can. Therefore, even if THz waves do cause any harm, it is limited to skin level.
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14. What Makes Terahertz Waves
Interesting ?
It’s Applications
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15. Applications
 As visible light can create a photograph
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16. Applications
Radio waves can transmit sound
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17. Applications
X-rays can see shapes within the human body
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18. Applications
So Terahertz waves (also called as T-rays) can create pictures and transmit information
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19. Applications
Further More THz radiation has widespread potential applications in
medicine,
microelectronics,
agriculture,
forensic science,
and many other fields.
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20. Some Specific Applications
1.Terahertz Imaging
2. Terahertz Spectroscopy
3. Manufacturing
4.Communication
5.Medical
6. Security
7. Monitoringof water/ice state in foodstuffs
8. Water content measurement in plants andseeds
9.Laser-terahertz
10. Nondestructive detection of illicit drugs
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21. Medical Imaging
Tera hertz is low photon energy so it does not harm living tissue and DNA.
Some frequencies can penetrate several mms of tissues with low water content and reflect
back.
Terahertz radiation can also detect differences in water content and density of a tissue.
Such methods could allow effective detection of epithelial cancer with an imaging system
that is safe, non-invasive, and painless.
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22. Manufacturing
There are many possible usages of manufacturing, quality control, and process monitoring.
In general plastics and cardboard being transparent to terahertz radiation, making it
possible to inspect packaged goods.
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23. Security
It can penetrate fabrics and plastics so it can be used in surveillance like security screening
to uncover the hidden weapons.
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24. Tera Hertz Sources
Terahertz are between microwave and infra red region,
There generation and detection is still not as good as it should have.
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25. Tera Hertz Sources
We can not measure tera hertz via electronic counters. So we use the proxy method with
the properties of wavelength and energy.
Generation and detection become impossible by conventional electronic devices. So we
require ne devices and techniques.
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26. Tera Hertz Sources
Tera Hertz Sources are divided into two sources
1)Natural
2)Artificial
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27. Tera Hertz Sources
Natural
Naturally tera hertz frequencies are emitted by black bodies with above 2k
Temperature
we measure these frequencies from distant objects like cold matter, dust
particle and distant star bust galaxies.
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28. Artificial
As of 2012, viable sources of terahertz radiation are the
Gyrotron Oscillator,
Backward wave oscillator ("BWO"),
Organic gas far infrared laser ("FIR laser").
Schottky diode multipliers
Varactor (varicap) multipliers.
Quantum cascade laser
Free electron laser (FEL),
Synchrotron light sources,
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29. Tera Hertz Detection
We detect tera hertz pulses by two methods.
1)Photoconductive Antennas
2)Electro-Optic Sampling
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30. Tera Hertz in Wireless Communication
Tera Hertz communication is divided into two scales
1) Macroscale
2)Nano/Micro Scale
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31. Macroscale
5G Cellular Networks
Terabit Wireless Local Area Networks (T-WLAN)
Terabit Wireless Personal Area Networks (T-WPAN)
Secure Terabit Wireless Communication
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32. 5G Cellular Networks
 By using Tera hertz small cells will provide ultra high
speed data communication within areas of 10 m.
 The operational environment of these small cells includes
static and mobile users, both in indoor and outdoor
scenarios.
 Specific applications are ultra-high-definition multimedia
streaming to smartphones, or ultra-high-definition video
conferencing.
 In addition, directional THz Band links
can be used to provide an ultra-high-speed wireless
backhaul to the small cells.
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33. Terabit Wireless Local Area Networks
(T-WLAN)
 THz Band communication enables the seamless
interconnection between ultra-high-speed wired
networks, e.g., fiber optical links, and personal
wireless devices such as laptops and tablet-like
devices (no speed difference between wireless and
wired links).
 This will facilitate the use of bandwidth-intensive
applications across static and mobile users, mainly
in indoor scenarios.
 Some specific applications are high-definition
holographic video conferencing or ultrahigh-speed
wireless data distribution in data centers.
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34. Terabit Wireless Personal Area Networks
(T-WPAN)
 Tbps links among devices in close
proximity are possible with THz
Band communication.
For example, to transfer the equivalent
content of a blue-ray disk to a tablet-
like device could take less than one
second with a 1 Tbps link, boosting
the data-rates of existing technologies
such as WiFi Direct
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35. Secure Terabit Wireless Communication
 The THz Band can also enable
ultra-broadband secure
communication links in the
military and defense fields.
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36. Nano/Microscale
Health Monitoring Systems
Nuclear, Biological and Chemical Defenses
The Internet of Nano-things
Ultra-high-speed On-chip Communication
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37. Health Monitoring Systems
 We can monitor different blood cholesterol, cancer
biomarkers and infectious agents by deploying
nanoscale sensors in body.
 So we can use Tbps link to collect data from sensor
nodes to cell phones or some special devices for
monitoring of data.
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38. The Internet of Nano-things
 The interconnection of nanoscale machines with
existing communication networks is known as the
Internet of Nano-Things (IoNT).
 In future it is possible that user can use Nano
devices to track his all professional and personal
items in effortless manner. So that is only possible
by the use of Tbps link
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39. Ultra-high-speed On-chip Communication
 We can use graphene based Nano antenna
with Tera hertz frequencies for ultra high
intercommunication of chips.
 This novel approach will fulfil all the
requirements like area constraints, high
bandwidth.
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40. Challenges
Producing and detecting coherent terahertz radiation remains technically challenging,
Although inexpensive commercial sources now exist in the 0.3–1.0 THz range (the lower
part of the spectrum), including gyrotrons, backward wave oscillators, and resonant-
tunneling diodes.
Currently THz systems cost up to $300,000 total, this is for sensing and imaging of THz
waves.
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41. Solutions
By using CMOS technology design economical devices for generation and detection.
So low cost CMOS Technology we can built a feasible solution.
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42. FAQs
Q1) What are Tera hertz Frequencies?
Ans: they are part of Electro Magnetic Spectrum.
Q2) Why we us them?
Ans: because they have high bandwidth and still unallocated.
Q3) Where they lie in spectrum?
Ans: They lie between microwave and infrared region.
Q4) How much energy they have?
Ans: @ 1THz it has 4.1 meV
Q5.How much wavelength they have?
Ans: 1mm to 0.1 mm
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43. FAQS
Q6) How much frequency they have?
Ans: 0.1 THz to 10 THz
Q7) How much time period?
Ans: at 1THz it has 1ps
Q8) When they were detected?
Ans: Since 1881
Q9) When they were generated?
Ans: 2012
Q10) Are they harmful?
Ans: No they aren’t.
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44. FAQs
Q11) Where we can use?
Ans: Different applications like imaging and wireless communication
Q12) Applications in wireless communications?
Ans: Network on chip and IOnT
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45. FAQS
Q13) Advantages/disadvantages of tera hertz ?
Ans: they are harmless , can be used in cancer detection, hidden instruments detection
Q14) Why to move towards tera hertz?
Ans: Due to Large Bandwidth
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46. Conclusion
More research is needed to continue developing THz wave applications.
As the equipment become more readily available
lower in cost they systems are likely to become more available.
Particularly, in the medical field great potential exists.
Once some of the challenges are met THz will become a true, practical benefit.
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47. References
All of Information is from the different sources readily available on google.com
Specially Wikipedia
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48. Ask Questions if you Have !!!
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