
Afshan BegumNational Institute for Materials Science | NIMS · Research Center for Electronic and Optical Materials
Afshan Begum
Ph.D.
https://samurai.nims.go.jp/profiles/afshan_begum
About
9
Publications
2,396
Reads
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6
Citations
Introduction
I specialize in Nanophotonics, Photonic Crystals, Dirac cones, & Topological Photonics.
Dirac cones can be precisely probed in photonics for crucial details in momentum space. I can formulate secular equations in optical material by semi-analytical methods. Then solve it for eigenfrequencies in both 2D/3D, using FEM. I can fabricate nanostructures using CMOS-compatible techniques. I probe Dirac cones using my group's specialized facility of high-angle resolution reflection IR spectroscopy.
Additional affiliations
May 2023 - present
Position
- Postdoctoral Researcher
Description
- I perform semi-analytical & Eigenfrequency calculations for n-layered material. My choice of computation is high-accuracy 3D-FEM, having achieved a reduced computational time in COMSOL by 30% in Photonic Crystal slabs. I perform material analysis by dispersion relation calculation. I can fabricate Photonic Crystal slabs, gratings & ring resonators in SOI compatible nanofabrication. I am now interested in thin-film deposition & analysis to enhance propagation constant.
April 2019 - April 2023
Position
- NIMS Junior Researcher
Description
- "Study on electromagnetic double Dirac cones and topological edge modes in photonic crystal slabs" I experimentally analysed topological edge modes and double Dirac cones by high-precision nanofabrication of distorted C6v-symmetric periodic lattice and high angle-resolution measurements at mid-infrared wavelengths, which finds its direct application in photonic crystal lossless waveguides, lasers and detectors.
July 2017 - March 2019
Publications
Publications (9)
We successfully fabricated silicon-on-insulator (SOI) photonic crystal (PhC) slabs in which electromagnetic topological band gaps and edge modes were materialized for symmetric transverse-electric-like modes. Because the structure of our specimens can be regarded as symmetric about the horizontal middle plane of the PhC slab, their symmetric and an...
We report on the first experimental observation of two-dimensional isotropic double Dirac cones in the electromagnetic dispersion relation, which were materialized by the accidental degeneracy of E1- and E2-symmetric eigenmodes on the Γ point of photonic crystals. We fabricated triangular-lattice photonic crystal slabs of the C6v symmetry on silico...
We study the angle-dependent reflection spectra of two-dimensional photonic crystal (PC) slabs, which we use for developing mid-infrared surface-emitting lasers. The PC design produces a perfect resonance between material gain frequencies and the [Formula: see text]-point band edge in the first Brillouin zone. Hence, we expect laser emission to occ...
Questions
Questions (2)
We've all been in circumstances when we couldn't find the literature we were looking for. Other times, we found exactly what we wanted, but very late.
Thus, beginners in research are pushed to formulate a clear and innovative title. Keywords rescue us, but, is it enough?
In these days of data mining, what tools can we utilize to structure our research paper titles such that they are search engine optimized (SEO)?
How can we write technical titles that are both engaging and readable?
1. Google Trends
Track changes in word usage over time, within a region, etc.
2. Web-of-Science
Regular keyword literature search, to find jargon usage.
3. Semrush
Helps with Keyword Research, Competitive Research, PR, etc. It is a marketing tool, perhaps used by industrial researchers and product developers?
4. What am I missing? What are your tricks and tips?
Thank you!
How can I check the regularity of my fabricated photonic crystal arrays? (for reference, one hole/pillar radius is 300 nm, can be either square lattice/triangle lattice).
I can measure the hole size by SEM, but cannot measure lattice constant, especially with 3mm by 3mm large arrays.