Experimental demonstration of reflection minimization at two-dimensional photonic crystal interfaces via antireflection structures

Kim, Teun-Teun; Lee, Sun-Goo; Kim, Myeong-Woo; Park, Hae Yong; Kim, Jae‐Eun

doi:10.1063/1.3176949

Cited by 24 publications

(23 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This type of coating has been demonstrated both theoretically [59] and experimentally [60], but the authors acknowledge that their method works only at relatively low frequencies where only one mode is involved at the interface. By separating a two-dimensional parameter search into two one-dimensional searches, the design problem becomes feasible despite the inefficiency of the simulations.…”

Section: Antireflection Coatingsmentioning

confidence: 99%

Photonic-crystal surface modes found from impedances

et al. 2010

View full text Add to dashboard Cite

We present a rigorous definition of a wave impedance for 2D rectangular and triangular lattice photonic crystals (PCs), in the form of a matrix. Reflection and transmission at an interface between PCs can be represented by matrices that relate the Bloch mode (eigenmode) amplitudes in the two PCs; we show that these matrices, which are multi-mode generalisations of reflection and transmission coefficients, may be calculated from the PCs' impedances that we define.Given the impedances and Bloch factors (propagation constants) of a collection of PCs, the reflection and transmission properties of arbitrary stacks of these PCs may be calculated efficiently using a few matrix operations. Therefore our definition enables PC-based antireflection coatings to be designed efficiently: some computationally expensive simulations are required in an initial step to find a range of PCs' impedances, but then the reflectances of every coating that consists of a stack of these PCs can be calculated without any further simulations.We first define the PC impedance from the transfer matrix of a single PC layer (i.e., a grating). Since transfer matrix methods are not especially widespread, we also present a method and associated source code to extract a PC's propagating and evanescent Bloch modes from a scattering calculation that can be performed by any off-the-shelf field solver, and to calculate impedances from the extracted modal fields.Finally, we put our method to use. We apply it to design antireflection coatings, nearly eliminating reflection at a single frequency for one or both polarisations, or lowering it across a larger bandwidth. We use it to find surface modes at interfaces between PCs and air, and their projected band structures. We use the impedance to define effective parameters for PC homogenisation, and we briefly describe how our definition has been used to dispersion engineer a PC waveguide. Statement of contribution for joint author publicationsLawrence, F. J. et al. "Antireflection coatings for two-dimensional photonic crystals using a rigorous impedance definition". Appl. Phys. Lett. 93, 1114Lett. 93, (2008 This Letter is partially based on work done in FL's Honours year, and partially on work done during his PhD. Most of the software used was provided by KD and LB, and FL extended it in collaboration with them. In FL's PhD he extended the software implementation of the method (with help from KD and LB) to support non-normal incidence and frequencies above the first Wood anomaly. FL wrote the letter, which was heavily edited and proofread by MdS, KD, and LB.Lawrence, F. J. et al. "Impedance of square and triangular lattice photonic crystals". Phys. Rev. A 80, 23826 (2009) The suggestion of generalising the method to triangular lattices was made by FL's supervisors. LB supplied the orthogonality relations, which as noted in the paper are from previous work, and FL worked out how to use these to define the impedance for these structures. LB suggested the final notation used in the paper. Taking the Ma...

show abstract

Section: Antireflection Coatingsmentioning

confidence: 99%

Photonic-crystal surface modes found from impedances

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The effective refractive indices of sonic crystals are evaluated at 0.1ωa 0 /2πc air . In this work, different from the approach used in [15][16][17], we do not scan the radius of ARC cylinders and the distance between the ARC and the sonic crystal to find the optimal transmission. For simplicity, we assume that the material parameters and the lattice constant in ARC structure are the same as the ones in the bending waveguide.…”

Section: Design Of Arcs For Bending Waveguidesmentioning

confidence: 98%

“…The antireflection coating (ARC) has been introduced to minimize the unwanted reflection from the surfaces of the optical devices based on photonic crystals [15,16]. The ARC structures are composed of rods (holes) at the interfaces between a two-dimensional photonic crystal and a homogeneous background medium to reduce the reflection.…”

Section: Introductionmentioning

confidence: 99%

Enhancing transmission efficiency of bending waveguide based on graded sonic crystals using antireflection structures

Chen

2012

Appl. Phys. A

View full text Add to dashboard Cite

The conventional antireflection coating (ARC) structure for sonic crystal devices is to place the cylinders at the interface between a sonic crystal device and a background medium. The radius of ARC cylinders and the distance between the ARC and the sonic crystal device are adjusted to obtain an optimal antireflection effect. We propose that ARC structures are directly designed by using the conventional ARC theory instead of scanning the geometric and spatial parameters of the conventional ARC structures. According to the concept of the effective refractive index of sonic crystals, the exact ARC structures can be implemented by sonic crystals. The transmission efficiency of a bending waveguide designed by graded sonic crystals can be enhanced by introducing the ARC structures based on sonic crystals. The performances of different ARC structure designs are compared and discussed.

show abstract

“…26 homogeneous dielectric layers that act as ARCs. In the following, such layers made of practically relevant ZnO are investigated.…”

Section: Sandwiching Intermediate Reflectors In Tandem Solar Cells Fomentioning

confidence: 99%

Sandwiching intermediate reflectors in tandem solar cells for improved photon management

Fahr

Rockstuhl

Lederer

2012

Applied Physics Letters

View full text Add to dashboard Cite

In tandem solar cells, intermediate reflectors are employed to increase light absorption in the top cell. Thus far, the use of photonic crystals for this purpose was not optimal since side-lobes in the reflection spectrum reduced the absorption in the bottom cell. To compensate this reduction, the bottom cell thickness had to be excessively increased; nullifying the main advantage of thin-film solar cells. Here, we suggest to solve this issue by reducing the impedance mismatch between photonic crystal and bottom cell using anti-reflection layers. The concept is even validated for solar cells comprising random textures.

show abstract

Experimental demonstration of reflection minimization at two-dimensional photonic crystal interfaces via antireflection structures

Cited by 24 publications

References 12 publications

Photonic-crystal surface modes found from impedances

Photonic-crystal surface modes found from impedances

Enhancing transmission efficiency of bending waveguide based on graded sonic crystals using antireflection structures

Sandwiching intermediate reflectors in tandem solar cells for improved photon management

Contact Info

Product

Resources

About