We present both experimental and numerical data showing the absorption of unpolarized, normally incident light by a gold crossed grating having a shallow sinusoidal profile. We show furthermore that the total absorption of unpolarized light can be achieved for an angle of incidence of 30 degrees with a crossed grating having its period adjusted appropriately from the normal incidence case to pr...

In this Letter, the optical properties of randomly positioned silicon nanowire arrays are studied. The result shows that position randomization with a filling ratio larger than 36% renders better absorptance over a broadband ranging from 300 to 1130 nm compared to regular structures. The ultimate efficiency of a 48% filling ratio position randomized nanowire structure is 13.4% higher compared t...

A combination of photocurrent and photothermal spectroscopic techniques is applied to experimentally quantify the useful and parasitic absorption of light in thin hydrogenated microcrystalline silicon (μc-Si:H) films incorporating optimized metal nanoparticle arrays, located at the rear surface, for improved light trapping via resonant plasmonic scattering. The photothermal technique accounts f...

Thermal radiative properties of thin graphitic petal arrays are theoretically and experimentally investigated. Finite-difference time-domain (FDTD) simulations are first performed to calculate optical properties of vertical graphitic arrays of different structures, namely, graphitic gratings, periodic graphitic cavities, and random graphitic cavities. For graphitic gratings, the absorptance and...

Relative absorptance of intact branches measured with an integrating sphere was compared to leaf area estimated by conventional methods (volume displacement and scanning area meter) for three conifer species: Picea mariana (Mill.) BSP, Pinus banksiana (Lamb.) and Pseudotsuga menziesii (Mirb.) Franco. A consistent relationship between relative absorptance and surface area emerged for the three s...

Elevated partial pressures of atmospheric carbon dioxide, similar to numerous causes of plant stress, may alter leaf pigmentation and structure and thus would be expected to alter leaf optical properties. Hypotheses that elevated CO(2) pressure and air temperature would alter leaf optical properties were tested for sugar maple (Acer saccharum) in the middle of its fourth growing season under tr...