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Temporal Cloaking Through Kerr Nonlinearity and Doppler Broadening

Thesis Info

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Author

Jabar, Mian Syed Abdul

Program

PhD

Institute

University of Malakand

City

Malakand

Province

KPK

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/9942/1/Mian_Syed_Abdul_Jabar_Physics_2018_UoM_Malakand_Main%20part.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727563784

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The newborn phenomenon of temporal cloaking is investigated under the e®ects of Doppler broadening and Kerr nonlinearity in di®erent atomic me- dia. The optical properties of these media are manipulated in such a manner that a time gap is created in the propagating probe light where events or information can be transmitted undetected. To create the cloaking time gap, the enhanced subluminal and superluminal behaviors of the probe ¯eld are focused. The opened temporal gap is closed by an inverse process that involves reverse modi¯cation of the optical properties of the medium. Ini- tially, we consider a ¯ve-level M-type atomic con¯guration of rubidium. The concept of Doppler broadening is introduced along with the superposition of the double resonant ¯elds in the system. Phase shift variations are caused in the medium which result into a signi¯cant delay and advancement of the probe pulse. The delay and advancement times lead to the generation of a time hole for concealing information in the temporal domain. A microsecond time gap is attained without signi¯cant distortion in the pulse shape. The time gap is further increased to several orders of microseconds with increase in the Doppler width. Next, we investigate propagation of the light pulse in a four-level Doppler broadened sodium atomic system. The possibility of creating a temporal gap is discussed on the basis of spectral hole burning in the system. The probe pulse is observed to delay in the hole burning region while it advances in the nearest neighboring region. A cloaking time gap of the order of microseconds is achieved in the slow and fast light regime. The time gap is modi¯ed with the inverse Doppler e®ect. The time gap can also be tuned and modi¯ed with the strengths of the coupling ¯elds, if the Doppler width is kept constant in the system. Finally, we extend our studies to the three-level rubidium atomic system. The pulse delay and advancement vi times are observed at speci¯c system parameters in the presence of self-Kerr ¯eld e®ect. The delay and advance times are enhanced with increase in the intensity of self-Kerr ¯eld. A cloaking time gap of the order of nanosecond is created in the observed fast and slow light. Increase of the time gap is observed with increase in the intensity of self-Kerr nonlinearity. The time gap is enhanced to several orders of nanosecond, su±cient to hide any prac- tical event. The time gaps are closed by reverse manipulation of the optical properties. Our results may contribute to strengthening the idea of hiding events in successive temporal gaps for achieving enhanced security of the communication systems.
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پروفیسر باور

پروفیسر باور
پچھلے مارچ میں جرمنی کے ہالے یونیورسٹی کے علوم مشرقیہ کے پروفیسر باور کا انتقال ہوگیا، وہ لسانیات کے ماہر تھے، وہ یورپ کی تقریباً جملہ زبانوں کے جاننے کے علاوہ ساری سامی زبانوں سے واقف تھے اور تورانی زبانوں خصوصاً چینی زبان میں خاص مہارت رکھتے تھے۔ اس حیرت انگیز وسیع لسانیاتی واقفیت کے سبب سے وہ راس شمرہ کی کھدائیوں میں بعض نئے خطوں کے کتبوں کے برآمد ہونے پر ان کو حل کرسکے، ماسوف علیہ کو امام غزالی کی احیاء العلوم سے خاص دلچسپی تھی، اس کے متفرق ابواب کے ترجمے اکثر شائع کرایا کرتے تھے، اسلامی علم مرایا و مناظر پر بھی بعض اچھے مضمون لکھے تھے، انسائیکلوپیڈیا آف اسلام کے شریک ناشر بھی تھے اور فلک، حاء، حفص الفرد، وغیرہ عنوانوں پر اس میں مقالے لکھے تھے، ’’حرف تہجی کی ابتداء‘‘ پر ان کی ایک جرمن تالیف اس وقت مطبع میں ہے۔ (سید سلیمان ندوی، جولائی ۱۹۳۷ء)

 

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For the better guidance of humanity and for the demonstration of His blessings and favor’s, The Lord of the Universe gave Religion of truth the title of Islam. This is the right path'' which is fundamental cause of sending the chain of prophets starting from Hazrat Adam (AS) to the Holy Prophet Mohammad (PBUH). Allah has declared it as His favored Deen and a complete code of life for humanity. This is clear from the history of Prophets (AS) that they had left no stone unturned in the propagation of the Divine message and used each and every kind of available resources so that the humans related to every domain of life must be influenced from the purity of its message. Submitting God’s belief is the responsibility and essential element of faith of muslim men and women. The indolence for spreading Islam is the indication of weakens of faith. As the Holy Prophet (PBUH) adopted all the techniques and modes of dissemination of the Divine message which all the prophets of yore had adopted. For the accomplishment of His mission he sustained lot of discomforts and tortures that even all the previous Prophets had not bore them collectively. The Holly Qur’an has shown variety of the Modus Operandi to the dissemination of the divine Message. Amongst all these the most important are, The Modus Operandi of waazz , Inzaar o Tabsheer, Amsaal 0 Qessas. All these modes play a vital role in this regard. The Holy Prophet (PBUH) utilized each and every mode for the dissemination of the Divine message so that, as a result, by the grace of Allah Almighty, people may say yes to it, thus the goal of Islam was achieved in such a way as the entire humanity was left dumbfounded. This was the mode of Allah’s final dispensation adopted by the Holy Prophet (PBUH) and his companions which brought about a great upheaval in the society. It is preserved in it’s unalloyed form to the present day. The need of the day is, to deduce those methods from the Holy Qur’an the adoption of which revolutionized the world some fourteen hundred years ago. Though the problems of modern times are complex and multidimensional, yet one can turn to the Holy Book for their best solution. Because the Qur’an is the book of guidance not for one specific era, but for all epochs and all ages.