The optical absorption properties of free-standing InAs nanomembranes of thicknesses ranging from 3 nm to 19 nm are investigated by Fourier transform infrared spectroscopy. Stepwise absorption at room temperature is observed, arising from the interband transitions between the subbands of 2D InAs nanomembranes. Interestingly, the absorptance associated with each step is measured to be ∼1.6%, ind...

Determination of particulate absorption in natural waters is often made by measuring the transmittance of samples on glass-fiber filters with the so-called quantitative filter technique (QFT). The accuracy of this technique is limited due to variations in the optical properties of the sample/filter composite, and due to uncertainties in the path-length amplification induced by multiple scatteri...

We measured the optical absorptance of superconducting nanowire single photon detectors. We found that 200-nm-pitch, 50%-fill-factor devices had an average absorptance of 21% for normally-incident front-illumination of 1.55-microm-wavelength light polarized parallel to the nanowires, and only 10% for perpendicularly-polarized light. We also measured devices with lower fill-factors and narrower ...

For ultrathin (~10 nm) nanocomposite films of plasmonic materials and semiconductors, the absorptance of normal incident light is typically limited to about 50%. However, through addition of a non-absorbing spacer with a highly reflective backside to such films, close to 100% absorptance can be achieved at a targeted wavelength. Here, a simple analytic model useful in the long wavelength limit ...

The excitation of multiple surface-plasmon-polariton (SPP) waves guided by the interface of a metal and a onedimensional photonic crystal in the grating-coupled configuration was studied both experimentally and theoretically. Only p-polarized incident light was considered in the visible and near-infrared regimes. When the absorptance was plotted against the angle of incidence, the excitation of...

We report the design of dielectric-filled anti-reflection coated (ARC) two-dimensional (2D) metallic photonic crystals (MPhCs) capable of omnidirectional, polarization insensitive, wavelength selective emission/absorption. Using non-linear global optimization methods, optimized hafnium oxide (HfO2)-filled ARC 2D Tantalum (Ta) PhC designs exhibiting up to 26% improvement in emittance/absorptance...

Dispersion characteristics of four types of superconducting nanowire single photon detectors, nano-cavity-array-(NCA-), nano-cavity-deflector-array-(NCDA-), nano-cavity-double-deflectorarray-(NCDDA-) and nano-cavity-trench-array-(NCTA-) integrated (A-SNSPD) devices were optimized in three periodicity intervals commensurate with half-, three-quarterand one surface plasmon polariton wavelength. T...

The quantum yield of photosystem II, determined by chlorophyll fluorescence and the quantum yield of CO2 uptake, determined from gas exchange, are two physiologically important measurements in clarifying the response to environmental stress. Both measurements, however, require an accurate assessment of leaf light absorption in the photosynthetically active radiation wavelength range (400–700 nm...

This program encompassed an analytical and experimental inveSLigdgion 0, the application of passive thermal control techniques to extravehicular flexible space garments in 300 nautical mile earth orbits. Results indicate that passive thermal control by varying the absorptance and emittance of the outer surface of the garment is not possible when internal heat generated is in excess of 1500 Btu/...

Efficient trapping of the light in a photon absorber or a photodetector can improve its performance and reduce its cost. In this paper we investigate two designs for light-trapping in application to infrared absorption. Our numerical simulations demonstrate that nonabsorptive pyramids either located on top of an absorbing film or having embedded absorbing rods can efficiently enhance the absorp...