Peter Bermel

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This paper describes Meep, a popular free implementation of the finite-difference time-domain (FDTD) method for simulating electromagnetism. In particular, we focus on aspects of implementing a full-featured FDTD package that go beyond standard textbook descriptions of the algorithm, or ways in which Meep differs from typical FDTD implementations. These(More)
Finite-difference time-domain (FDTD) methods suffer from reduced accuracy when modeling discontinuous dielectric materials, due to the inhererent discretization (pixelization). We show that accuracy can be significantly improved by using a subpixel smoothing of the dielectric function, but only if the smoothing scheme is properly designed. We develop such a(More)
M. Ghebrebrhan,1,* P. Bermel,2,3,4 Y. X. Yeng,5 I. Celanovic,4 M. Soljac̆ić,1,4 and J. D. Joannopoulos1,4 1Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 2Center for Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 3Research Laboratory of(More)
We demonstrate the possibility of achieving enhanced frequency-selective near-field radiative heat transfer between patterned (photonic-crystal) slabs at designable frequencies and separations, exploiting a general numerical approach for computing heat transfer in arbitrary geometries and materials based on the finite-difference time-domain method. Our(More)
<p> <a href="">Focus Serial: Frontiers of Nonlinear Optics</a> </p>Nonlinear photonic-crystal microresonators offer unique fundamental ways of enhancing a variety of nonlinear optical processes. This enhancement improves the performance of nonlinear optical devices to such an extent that their corresponding(More)
Most photovoltaic (solar) cells are made from crystalline silicon (c-Si), which has an indirect band gap. This gives rise to weak absorption of one-third of usable solar photons. Therefore, improved light trapping schemes are needed, particularly for c-Si thin film solar cells. Here, a photonic crystal-based light-trapping approach is analyzed and compared(More)
The front-coating (FC) of a solar cell controls its efficiency, determining admission of light into the absorbing material and potentially trapping light to enhance thin absorbers. Single-layer FC designs are well known, especially for thick absorbers where their only purpose is to reduce reflections. Multilayer FCs could improve performance, but require(More)
The challenging problem of ultra-high-energy-density, high-efficiency, and small-scale portable power generation is addressed here using a distinctive thermophotovoltaic energy conversion mechanism and chip-based system design, which we name the microthermophotovoltaic (μTPV) generator. The approach is predicted to be capable of up to 32% efficient(More)
While silicon (Si) is the most widely used material for solar energy harvesting, it suffers from having an indirect bandgap, which dictates that a relatively thick Si material is required to absorb a signifi cant portion of the solar spectrum. With cost a major concern for the photovoltaic industry, thinner fi lms with enhancements in material effi ciency(More)