Spatially Shaping Waves to Penetrate Deep inside a Forbidden Gap

Uppu, Ravitej; Adhikary, Manashee; Harteveld, Cornelis A.M.; Vos, Willem L.

doi:10.1103/physrevlett.126.177402

Cited by 24 publications

(11 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the current study is conducted on diffusive systems, our experimental platform and methodology can be employed to investigate deposition eigenchannels in 2D localized samples, where the transport is dominated by the highest-transmission eigenchannel. It may also be used to explore energy deposition inside disordered photonic crystals 53 and coupled resonator optical waveguides, which are essential building blocks in on-chip photonic circuits.…”

Section: Discussionmentioning

confidence: 99%

Depth-targeted energy delivery deep inside scattering media

et al. 2022

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Depth-targeted energy delivery deep inside scattering media

et al. 2022

View full text Add to dashboard Cite

“…To enhance the weak absorption of silicon above the electronic band gap at wavelengths in the range 600 nm < λ < 1100 nm, we tailor the lattice parameters of the inverse woodpile photonic crystal to a = 425 nm and c = 300 nm such that the band gap is in the visible range. The chosen lattice parameters are 37% smaller than the ones usually taken for photonic band gap physics in the telecom range [39][40][41][42][43][44][57][58][59]. The required dimensions are well within the feasible range of nanofabrication parameters [60][61][62].…”

Section: Absorbing Boundarymentioning

confidence: 99%

Enhanced Absorption in thin and ultrathin silicon films by 3D photonic band gap back reflectors

Sharma,

Hasan,

Saive

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Since thin-film silicon solar cells have limited optical absorption, we explore the effect of a nanostructured back reflector to recycle the unabsorbed light. As a back reflector we investigate a threedimensional (3D) photonic band gap crystal made from silicon that is readily integrated with the thin films. We numerically obtain the optical properties by solving the 3D time-harmonic Maxwell equations using the finite-element method, and model silicon with experimentally determined optical constants. The absorption enhancement relevant for photovoltaics is obtained by weighting the absorption spectra with the AM 1.5 standard solar spectrum. We study thin films in two different regimes, much thicker (LSi = 2400 nm) or much thinner (LSi = 80 nm) than the wavelength of light. At LSi = 2400 nm, the 3D photonic band gap crystal enhances the spectrally averaged (λ = 680 nm to 880 nm) silicon absorption by 2.22× (s-pol.) to 2.45× (p-pol.), which exceeds the enhancement of a perfect metal back reflector (1.47 to 1.56×). The absorption is considerably enhanced by the (i) broadband angle and polarization-independent reflectivity in the 3D photonic band gap, and (ii) the excitation of many guided modes in the film by the crystal's surface diffraction leading to greatly enhanced path lengths. At LSi = 80 nm, the photonic crystal back reflector yields a striking average absorption enhancement of 9.15×, much more than 0.83× for a perfect metal. This enhancement is due to a remarkable guided mode that is confined within the combined thickness of the thin film and the photonic crystal's Bragg attenuation length. An important feature of the 3D photonic band gap is to have a broad bandwidth, which leads to the back reflector's Bragg attenuation length being much shorter than the silicon absorption length. Consequently, light is confined inside the thin film and the remarkable absorption enhancements are not due to the additional thickness of the photonic crystal back reflector.

show abstract

“…After significant advances in nanoscience techniques, particularly with the experimental progress in custom beam shaping, 1, 2 complex wavevectors have opened up an interesting window realm of intriguing anomalous technologies, including forbidden band transmission, 3 exceptional points engineering, 4 polarisation-loss locking 5 or imaging through scattering media. 6 In this article, we propose an approach based on complex wavevectors for effective propagating modes within non-transparent media.…”

Section: Introductionmentioning

confidence: 99%

Material losses in Helmholtz equation: from polarisation-loss locking to lossy wave-vectors transmission via passive metasurface

Perea-Puente¹,

Rodríguez-Fortuño²

2023

SPIE Future Sensing Technologies 2023

View full text Add to dashboard Cite

Yielding on the intimate link between losses and polarization of the evanescent profile in optical waveguide via complex wave-vector polarization-loss locking phenomena was discussed in the context of spin orbit interactions of light. Inspired by this, we conducted an investigation into a novel method to achieve improved transmission of light across optically opaque materials showing Helmholtz equation solution for complex values introducing a passive metasurface placed on the boundaries of the material, affecting transmission coefficients for phase and amplitude simultaneously. This approach resulted in a non-monotonic beam penetrating inside the lossy material, enhancing its intensity while reducing its amplitude near the interface. Such proposal have interesting applications in various scenarios, including acoustic isolation, sensing technologies via grid metasurface matching, improved telecommunications transmission in homogeneous materials, or enhanced laser resilience in biological tissues for subcutaneous imaging or treatment. Furthermore, our theoretical approach paves the way for potential realization in similar physical systems, ranging from near-zero-index materials to purely plasmonic interfaces, offering a comprehensive overview of the formalism.

show abstract

Spatially Shaping Waves to Penetrate Deep inside a Forbidden Gap

Cited by 24 publications

References 57 publications

Depth-targeted energy delivery deep inside scattering media

Depth-targeted energy delivery deep inside scattering media

Enhanced Absorption in thin and ultrathin silicon films by 3D photonic band gap back reflectors

Material losses in Helmholtz equation: from polarisation-loss locking to lossy wave-vectors transmission via passive metasurface

Contact Info

Product

Resources

About