It is the presentation of the paper "The accomplishment of the phenomenon of perfect optical cloaking using a multi-lens system" which was presented in the conference " First iiScience International Conference 2020" on 3rd March 2020. Which is published in the proceedings of SPIE (IF: 0.56) Here is the Doi of the paper : DOI: 10.1117/12.2574944 and here are the links of paper: https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11561/2574944/The-accomplishment-of-the-phenomenon-of-perfect-optical-cloaking-using/10.1117/12.2574944.full?SSO=1 https://www.researchgate.net/publication/343936005_The_accomplishment_of_the_phenomenon_of_perfect_optical_cloaking_using_a_multi-lens_system

2. Accomplishment of the
Phenomenon of Perfect Optical
Cloaking Using A Multi-Lens System
Making Invisibility Possible
Muhammad Miqdad Khan
Dept. of Physics
NED UET
Rafey Iqbal Rahman
Dept. of Management
CloudSynergi, Karachi

3. Inspired perhaps by Harry Potter’s invisibility cloak, scientists have recently developed several ways—some simple
and some involving new technologies—to hide objects from view. The latest effort, developed at the University of
Rochester,

4. What is Cloaking?
• The term 'cloaking' is usually misunderstood in the sense that the phenomenon
involves a piece of cloth, usually known as the “invisibility cloak”, which tends to
hide the object placed under it as shown in the famous Harry Potter series.
However, cloaking is much more than that.
• The mind-boggling phenomenon of cloaking allows us to induce invisibility in
objects, both in a partial manner as well as a whole. What actually happens is that
the light passes through an object as if it is not there at the moment. Since the
scientists and physicists are still unable to fully 'uncloak' the cloaking
phenomenon, only a handful of applications possessing social and of course,
technological impact have been discovered. Even the inclusion and incorporation
of the nanotechnology intended for the expansion and enhancement of the
cloaking phenomenon has not contributed much.

5. Some Applications
• The applications and usage in the defense sector are still not
deciphered in particular, however, on the other hand, the enablers of
the researches, both past and ongoing, in science and technology
have disclosed
• its applications in the health care and automotive sectors in the form
of the aspired advent of careful, precision-based, error-reduced
human surgeries (health care) and road accident prevention
technologies (automotive)

6. Previous Attempts
Natural resources formed inside the earth's crust are observing a significant
decline in their quantity on a daily basis. Owing to the trend towards the
plunge and lacking, the scientific laboratories undertook the task of the
creation of artificial or man-made resources in order to cope up with the
population growth and its requirements and the enhancement of the
lifestyle of the man-in-the-street and the people, alongside curbing the
adverse effect being generated by the act of exploitation of the natural
resources. Such an artificial resource was created by the name of
"Metamaterial". The metamaterial was created in order to surpass the
characteristics that the naturally-occurring materials possess and exhibit.
An application of metamaterial is found in the metamaterial cloaking
technique. However, the creation of a metamaterial is quite difficult and
cumbersome, although many advances have been made in science and
technology. Therefore, in comparison, another technique possessing the
name of "paraxial ray cloaking" is deemed to be quite convenient.

7. Theory
2.1.1 Two Lens System
𝑭𝟏 = 𝑭𝟐 = 𝑭 (1)
L1 L2
R1
R2
F
𝒅 = 𝒇𝟏 + 𝒇𝟐 (2)
Figure.1 Diagrammatic representation of a two-lens system

8. MATLAB calculation for system ray transfer matrix

9. Cloaked Region
There exists a limitation that no matter how fine the lens is, the
phenomenon of spherical aberration is witnessed. The spherical
aberration refers to the phenomenon where the focus point is not
unique. The focal length somehow portrays a nature of
dependency on the wavelength of the light. So, on behalf of the
above-said statement, it can be confidently said that:
𝑽𝒄𝒚 = 𝝅𝒓𝟐𝒉 (3)
𝑽𝒄𝒚 = 𝟑𝑽𝒄 (5)
𝑽𝒄 = 𝝅𝒓𝟐 𝒉 𝟑 (4)
2𝑹𝑪𝑳 = 𝑹𝑼𝑪𝑳 (6)
2𝑹𝑪𝑳 ≤ 𝑹𝑼𝑪𝑳 (7)

10. Four Lens System
The formula for calculating the total length of the cloaking apparatus, as described in prior research is as follows:
𝐿 = 2𝑡1 + 𝑡2 (𝑓1 + 𝑓2) / (𝑓1 − 𝑓2) (8)
As described in Eq. (1), the focal lengths of the lenses used in this experiment hold the same value, 40 cm. Therefore, as stated
previously, due to the inclusion of heavy mathematical equations, the phenomenon of optical cloaking did not prove to be practical
and feasible. The impracticality driven by the above-stated Eq. (8) can be observed as:
𝐿 = 2𝑡1 + 𝑡2 (40 + 40) / (40 − 40)
This results in the observation of an infinite cloaked region, however, for a cloaking phenomenon to be physically feasible, the
cloaked region must be of a finite or determined value.
Also, as described in prior research, the distance between the two pairs of lenses (t2) is as follows6,14:
t2 = 2f2 (f1+ f2) / (f1−f2) (9)
Again, with the similar approach, as it is known as f1 = f2 = f = 40 cm, therefore Eq. (9) becomes:
𝑡2 = 2𝑓2 (40 + 40) / (40 − 40)
From Fig. it is also proved that the distance between the two pairs of lenses does not matter.

11. Experimental Setup
Similar to the two-lens approach, we
will use two sets of a pair of lenses (L1),
(L2), (L3) and (L4). As we can see in the
Fig. that the rays between the two sets of
lenses are parallel. Since the distance
poses no threat in this case and could be
of any value greater than zero. The
reason that the distance could not be kept
equal to zero is that the problem of the
combination of the lens will occur. Then
the whole system would be wrongly
perceived as a three-lens system.

13. Results Discussion
Perfect cloaking is achieved since the background formed is original and erect. The four-lens cloaking
technique is the perfect cloaking. If we scale up the diameters of the lenses, larger objects can be hidden
too. The experimental setup used allows perfect paraxial ray optical cloaking up to 15º.
CONCLUSIONS
The experiments performed regarding the perfect paraxial ray optical cloaking yielded satisfactory results
along with some limitations and future recommendations for further research on the subject and the area
of interest.
The conclusions drawn from this research can be reported as:
Perfect paraxial ray optical cloaking is achieved without providing any significant amount of
consideration to the distance between the lenses.
The research is limited to hiding or cloaking of an object smaller in size due to the small diameter of lens
used in the series of experiments and the prototyping.

14. ACKNOWLEDGEMENT
We are highly indebted to Dr. Muhammad Imran Ahmed Siddiqui of
University of Karachi for his guidance and constant supervision as well
as for providing necessary information regarding this research and also
for his support in completing this endeavor.

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16. THANK YOU
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