Constantly increasing demand of renewable and nonpolluting energy production methods has made solar cells one of today's hottest research areas. Developing more cost-effective fabrication methods that enable production of extremely non-refl ecting surfaces is one of the key issues in solar cell research. [ 1 , 2 ] Many other applications, such as miniaturized chemical analysis systems, would also benefi t greatly from low-cost surfaces with low and uniform refl ectivity. [ 3 ] Typically, suppression of Fresnel refl ection has been achieved by antirefl ective coatings, but they suppress refl ection effi ciently only in a narrow wavelength range. Suppression of refl ection over a broad spectral range can be achieved by using nanotextured surfaces that form a graded transition of the refractive index from air to the substrate. [ 1 , 2 , 4-12 ] Here, we present a scalable, high-throughput fabrication method for such non-refl ecting nanostructured surfaces. Original nanostructures are etched on a silicon wafer and replication methods enable their transfer into polymeric materials. Previously, transfer of non-refl ecting structures into polymeric materials has not received enough attention. The fabrication starts with a maskless plasma-etching step, which forms nanosized spikes on a silicon substrate. Using the Taguchi method, [ 13 ] we show that the sidewall angles and heights of the nanospikes are controlled by the plasma-etching parameters. A silicon surface with pyramidshaped nanospikes serves as a template in the fabrication of an elastomeric stamp, which enables replication of the original nanospike pattern into polymeric materials. Denser nanospike arrays with steeper sidewalls suppress the refl ection of light most effi ciently, but they are not well-suited for replication. The refl ection measurements show that all implemented nanostructured surfaces greatly reduce the refl ection of light over a broad spectrum and that the size of the nanospikes contributes substantially to the antirefl ection properties. Our application for non-refl ecting surfaces is laser desorption ionization mass spectrometry (LDI-MS), which is a common technique in chemical analysis. [ 3 , 14 ] As a consequence of suppressed light refl ection, lower laser fl uence is enough to desorb and ionize the analytes from a nanostructured surface. We also make the surfaces self-cleaning by coating them with a low surface energy fl uoropolymer. High-throughput fabrication of low-cost self-cleaning surfaces, which suppress the refl ection of light over a wide spectral range, is expected to have applications ranging from chemical analysis of drugs and biomolecules to photovoltaics.

The International Commission on Illumination (CIE) has published a recommended system for mesopic photometry based on visual performance. The system provides means for determining mesopic photometric values based on measuring the spectral composition and intensity of light. The system uses an iterative calculation method. We investigate the conditions under which this system is applicable and identify potential problems with the iterative method. We show that the system works well for the vast majority of lighting applications. However, it has non-convergence and discontinuity issues for sources with very high and very low values of scotopic-photopic ratio. A set of parameterised formulae is presented that approximates the mesopic model and provides a continuous, closed-form solution for the adaptation level in all lighting conditions.

Stray light in single-monochromator Brewer instruments increases the uncertainty of solar UV spectral irradiance measurements and ozone retrievals. To study how spectral irradiance within and outside the measurement ranges of the instruments affects the stray light, two Brewer MKII instruments were characterized for the level of in-and out-of-range stray light at multiple laser wavelengths. In addition, several solar-blind filters utilized in single-monochromator Brewers to limit out-of-range stray light were characterized for spectral and spatial transmittances. Finally, the measurement results were used to simulate the effect of stray light and stray light correction on the spectral irradiance and ozone measurements at different wavelength regions. The effect of stray light from wavelengths above 340 nm was found to be negligible compared to other sources of uncertainty. On the other hand, contribution from wavelengths between 325 nm and 340 nm can form a significant portion of the overall stray light of the instrument, with 325 nm being the upper limit of the nominal measurement range of the instrument.

A bilateral comparison of the spectral irradiance scales between MIKES (Finland) and NIMT (Thailand) was carried out at 22 wavelengths between 290 nm and 900 nm. MIKES acted as the pilot and link to the results of the key comparison CCPR-K1.a. The spectral irradiance values measured by NIMT generally agree with the key comparison reference value within the expanded uncertainty. Only exceptions are results at wavelengths 300 nm, 450 nm, and 500 nm, where the ratios between the degree of equivalence (DoE) and the expanded uncertainty of DoE (k = 2) are 1.0, 1.4, and 1.2, respectively.