Seminar on Rigorous Characterization of Photonic Crystal Fibers
by using the Finite Element Method
will be held at Electrical Engineering Department
on Monday, 27th April, 2009 by
B.M. Azizur Rahman
School of Engineering and Mathematical Science City University,
Northampton Square, London
All the faculty members of Electrical Engineering, Computer Science Departments and the Graduate students are encouraged to attend the seminar.
Venue: Electrical Engineering Department, U.E.T., Lahore,
Days: Monday, 27th April, 2009
Time: 10:00 AM (Sharp)
Rigorous Characterization of Photonic Crystal Fibers by using the Finite Element Method
Photonic crystal fiber (PCF) or ‘holey fiber’ is a more exotic micro-structured optical fiber, where arrays of holes run along the waveguide length. In a PCF, the number of holes and their sizes, shapes, orientations and placements as well as the dielectric material used can provide an additional degree of freedom, which is not present in conventional fiber. A wide range of potential applications is anticipated, exploiting the ability to tailor the group velocity dispersion (GVD) and achieve adjustable spot-size, Raman amplification, Brillion laser action, second harmonic generation, four-wave mixing, super continuum generation, and creating polarization maintaining PCFs with higher modal birefringence.
To date, most of the research into these fibers has had a strong experimental basis , which has recently been complemented by various modal solution approaches to their characterization, but mostly using scalar formulations or being limited to specific types of structures. The modal solution approach, based on the powerful finite-element method (FEM) is more flexible, and can be used to represent any arbitrary cross-section accurately. This method has been widely used to find the modal solutions of a wide range of optical waveguides . The flexibility of the FEM to represent the cross-section of a holey fiber with arbitrary hole sizes and placements makes it a powerful technique, where many other simpler and semi-analytical approaches would be unsatisfactory. The variations of the effective index, power confinement, spot-size, modal hybridness, single-mode operation, GVD, leakage loss, bending loss, optimization of modal birefringence and polarization beat length with the waveguide parameters will be presented in this talk.
 J C Knight, T A Birks, P St J Russell, and D M Atkin, ‘All-silica single-mode optical fiber with photonic crystal cladding’, Opt. Lett., 21, pp.1547-1549, 1997.
 B M A Rahman and J B Davies, ‘Finite-element solution of integrated optical waveguides,’ J. Light wave Tech., 2, pp.682-688, 1984.
Brief Introduction of speaker
In 1976, B. M. Azizur Rahman received his BEng (Electrical) degree from Bangladesh University of Engineering and Technology and joined there as a lecturer. He received two gold medals in 1976 and 1979, for being the best undergraduate student and best postgraduate student of the whole university. In 1979, he received a Commonwealth Scholarship and in 1982 he completed his PhD degree in Electronics from University College London. Now he is a full Professor and Assistant Dean of Engineering at City University of London, where he leads the research group on Photonics Devices Modeling. He has published more than 350 journal and conference papers and his journal papers have been cited more than 1400 times. Prof. Rahman is a Senior Member of IEEE (USA), and Member of the Optical Society of America, and Member of IEE (UK).