**Publications**
S. Maayani, R. Dahan, Y. Kligerman, E. Moses, A. U. Hassan, H. Jing, F. Nori, D. N. Christodoulides and T. Carmon

"Flying couplers above spinning resonators generate irreversible refraction"

Nature, 558(7711), pp. 569

Absar Ulhassan

"Non-Hermitian Optics"

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in CREOL, The College of Optics and Photonics at the University of Central Florida Orlando

2018

Fan Wu, Absar U. Hassan, Mohammad A. Eftekhar, and Demetrios N. Christodoulides

"Universal Entropic Response of Nonlinear Multimode Optical Systems
"

CLEO: QELS_Fundamental Science. Optical Society of America, 2018.

A.U. Hassan, G.L. Galmiche, G. Harari, P.L. Likamwa, M. Khajavikhan, M Segev, and D.N. Christodoulides

"Chiral state conversion without encircling an exceptional point"

Physical Review A, 96(5), 052129

H. Hodaei, A.U. Hassan, S. Wittek, H. Garcia-Gracia, and R. El-Ganainy

"Corrections & amendments"

Nature, 551, pp. 30

2017

A.U. Hassan, B. Zhen, M. Soljacic, M. Khajavikhan, and D.N. Christodoulides

"Dynamically encircling exceptional points: exact evolution and polarization state conversion"

Physical Review Letters, 118(9), pp. 093002

2017

H. Hodaei, A.U. Hassan, S. Wittek, H. Garcia-Gracia, R. El-Ganainy, D.N. Christodoulides, and M. Khajavikhan

"Enhanced sensitivity at higher-order exceptional points"

Nature, 548(7666), pp. 187. Related articles: OPN: https://www.osa-opn.org/home/articles/volume_29/january_2018/departments/exceptional_points_an_emerging_tool_for_sensor_ap/, Physics Today: http://physicstoday.scitation.org/doi/full/10.1063/PT.3.3717

H. Hodaei, A.U. Hassan, H. Garcia-Gracia, W.E. Hayenga, D.N. Christodoulides, and M. Khajavikhan

"Enhanced sensitivity in PT-symmetric coupled resonators"

Laser Resonators, Microresonators, and Beam Control XIX, Proceedings of SPIE, 10090

H. Hodaei, A. U. Hassan, S. Wittek, M. Parto, H. Garcia-Garcia, R.A.H. El-Ganainy, D.N. Christodoulides, M. Khajavikhan

"Higher-order exceptional points in photonic systems"

SPIE Optics and Photonics, San Diego, California

H. Hodaei, A. U. Hassan, S. Wittek, M. Parto, H. Garcia-Garcia, R.A.H. El-Ganainy, D.N. Christodoulides, M. Khajavikhan

"Higher-order exceptional points in photonic systems"

Active Photonic Platforms IX, Vol. 10345, pp. 1034523

A. Kazemi Jahromi, A.U. Hassan, D.N. Christodoulides, and A.F. Abouraddy

"Observation of a parity-time-symmetry phase transition in a fiber cavity"

Conference on Lasers and Electro-Optics (CLEO), San Jose, California, JTu5A.51

A. K. Jahromi, A. U. Hassan, D. N. Christodoulides, and A. F. Abouraddy

"Observation of parity-time-symmetry phase transition in a fiber cavity"

San Jose, CA, CLEO 2017

A.U. Hassan, B. Zhen, M. Soljacic, M. Khajavikhan, and D.N. Christodoulides

"Polarization state conversion through exceptional point encirclement"

Conference on Lasers and Electro-Optics (CLEO), San Jose, California, FTh3D.1

H. Hodaei, A.U. Hassan, D.N. Christodoulides, and M. Khajavikhan

"Pt-symmetric micro-resonators: high sensitivity at exceptional points"

Conference on Lasers and Electro-Optics (CLEO), San Jose, California, FTh3D.2

A. K. Jahromi, A. U. Hassan, D. N. Christodoulides, and A. F. Abouraddy

"Signatures of exceptional points in statistical non-Hermitian optical cavities"

IEEE IPC, Orlando, FL, 2017

2017

A.K. Jahromi, A.U. Hassan, D.N. Christodoulides, and A.F. Abouraddy

"Statistical parity-time-symmetric lasing in an optical fibre network"

Nature Communications, 8(1), 1359

2017

J. Ren, H. Hodaei, G. Harari, A. U. Hassan, W. Chow, M. Soltani, D.N. Christodoulides, and M. Khajavikhan

"Ultrasensitive micro-scale parity-time-symmetric ring laser gyroscope"

Optics Letters, 42(8), pp. 1556-1559

J. Ren, G. Harari, A. Hassan, W. Chow, M. Soltani, D.N. Christodoulides, and M. Khajavikhan

"Ultrasensitive parity-time-symmetric micro-ring laser gyroscope"

IEEE Photonics Conference (IPC), Orlando, FL

H. Hodaei, A.U. Hassan, W.E. Hayenga, M.A. Miri, D.N. Christodoulides, and M. Khajavikhan

"Dark-state lasers: mode management using exceptional points"

Optics Letters 41(13), pp.3049-3052

2016

H. Hodaei, A.U. Hassan, J. Ren, W.E. Hayenga, M.A. Miri, D.N. Christodoulides, and M. Khajavikhan

"Design considerations for single mode microring lasers using parity-time-symmetry"

IEEE, Journal of Selected Topics in Quantum Electronics

2016

A.U. Hassan, H. Hodaei, M.-A. Miri, M. Khajavikhan, and D.N. Christodoulides

"Integrable nonlinear parity-time-symmetric optical oscillator"

Physical Review E, 9394), 042219

M. Heinrich, H. Hodaei, M.A. Miri, A.U. Hassan, W.E. Hayenga, D.N. Christodoulides, M. Khajavikhan

"Non-Hermitian microring systems: PT-symmetric lasers, mode management and enhanced emission efficiency"

Advanced Electromagnetic Materials in Microwaves and Optics, September

A.U. Hassan, H. Hodaei, M.A. Miri, M. Khajavikhan, and D.N. Christodoulides

"Nonlinear reversal of PT-symmetric phase transition in a system of coupled micro-ring cavities"

SPIE 9920, Active Photonic Materials VIII, September

A. K. Jahromi, A. U. Hassan, D. N. Christodoulides, and A. F. Abouraddy

"Observation of robust statistical parity-time symmetry breaking in ultra-long cavities"

29th Annual Conference of the IEEE Photonics Society, Waikoloa, Hawaii, 2 - 6 October

2016

A.U. Hassan, H. Hodaei, M.A. Miri, D.N. Christodoulides, and M. Khajavikhan

"Reversing the transition from an unbroken to a broken phase in a PT-symmetric dimer laser"

CLEO, San Jose, CA, June, paper FTh1A.1

A. K. Jahromi, A. U. Hassan, D. N. Christodoulides, and A. F. Abouraddy

"Robust statistical parity-time symmetric lasers in fiber cavities"

Frontiers in Optics, paper JW4A.100

2016

H. Hodaei, M.A. Miri, A.U. Hassan, W.E. Hayenga, M. Heinrich, D.N. Christodoulides, and M. Khajavikhan

"Single mode lasing in transversely multi-moded PT-symmetric microring resonators"

Laser & Photonics Reviews 10(3), pp.494-499

2016

H. Hodaei, A.U. Hassan, J. Ren, W.E. Hayenga, D.N. Christodoulides, and M. Khajavikhan

"Ultra-sensitive PT-symmetric coupled cavities"

CLEO, San Jose, CA, June, paper FTh1A.3

2015

A. Hassan, H. Hodaei, W. Hayenga, M. Khajavikhan, D. Christodoulides

"Enhanced sensitivity in parity-time-symmetric microcavity sensors"

OSA Advanced Photonics Conference, Boston, Massachusetts, SeT4C.3

2015

A.U. Hassan, H. Hodaei, M.A. Miri, M. Khajavikhan, D.N. Christodoulides

"Nonlinear reversal of the PT-symmetric phase transition in a system of coupled semiconductor microring resonators"

Physical Review A 92(6), pp.063807

2015

H. Hodaei, M.A. Miri, A.U. Hassan, W.E. Hayenga, M. Heinrich, D.N. Christodoulides, M. Khajavikhan

"Parity-time-symmetric coupled microring lasers operating around an exceptional point"

Optics Letters 40(21), pp.4955-4958

2015

A. U. Hassan, N. Nye, M. Khajavikhan, R. El-Ganainy. D. N. Christodoulides

"Ultra-sensitivity using higher order exceptional points"

The Ninth IMACS International Conference on Nonlinear Evolution Equations and Wave Phenomena: Computation and Theory, Georgia-Athens, Session 31