Blue Radiation Research Articles

Concentration effect of Tm3+ ions doped B2O3-Li2CO3-BaCO3-CaF2-ZnO glasses: Blue laser and radiation shielding investigations

Tm3+ ions doped barium lithium calcium zinc fluoroborate (BLCZFB) glasses with high photoluminescence and shielding properties were prepared with melt quenching technique. Their amorphous nature was confirmed with X-ray diffraction analysis. Their visible emission spectra show one high intense emission at 453 nm (22075 cm−1) corresponding to 1D2→3F4 transition, and their near infrared emission spectra show one broad emission located at 1528 nm (6544 cm−1) corresponding to 3H4→3F4 transition. Besides, the high energy gamma ray interaction parameters, including the mass attenuation coefficient (μ/ρ), and the effective atomic number (Zeff), etc., were also calculated for all glasses with Phy-X/PSD program. In general, 0.5TmBLCZFB glass exhibits a good luminescence in both visible and near-infrared regions, which can be suitable for solid state visible laser, optoelectronic devices, while 2TmBLCZFB glass expresses the best attenuating characteristics and potential applications for shielding.

Manipulation of the quantum dots photostability using gold nanoparticles

The effect of plasmonic films containing gold nanoparticles of different shape (nanospheres and nanorods) on the photostability of InP/ZnSe/ZnSeS/ZnS and CdSe/ZnCdS/ZnS quantum dots with core/shell structure has been determined. Gold nanospheres increase the photostability of InP/ZnSe/ZnSeS/ZnS quantum dots when excited by blue LED radiation when reducing the average lifetime of the excited state of quantum dots and, accordingly, when reducing the probability of Auger processes. An increase in the average lifetime of the excited state of CdSe/ZnCdS/ZnS quantum dots in complexes with gold nanorods leads to a decrease in the photostability upon excitation at 449 and 532 nm.

Sb3+–Er3+‐Codoped Cs2NaInCl6 for Emitting Blue and Short‐Wave Infrared Radiation

AbstractCs2NaInCl6 double perovskite is stable, environmentally benign and easy to prepare. But it has a wide band gap (5.1 eV), and therefore, does not show optical and optoelectronic properties in the visible and short‐wave infrared (SWIR) region. Here we introduce such functionalities in Cs2NaInCl6 by codoping Sb3+ (s‐electron doping) and Er3+ (f‐electron doping) ions. Sb3+ doping introduces optically allowed 5s2 5s15p1 electronic absorption at the sub‐band gap level, which then emits blue photoluminescence with ≈93 % quantum yield. But f‐f electronic absorption of Er3+ is parity forbidden. Codoping Sb3+–Er3+, leads to transfer of excitation energy from Sb3+ to Er3+, yielding SWIR emission at 1540 nm. Temperature (6 to 300 K) dependent photoluminescence measurements elucidate the excitation and emission mechanism. A phosphor converted light emitting diode (pc‐LED) fabricated by using the codoped sample emits stable blue and SWIR radiation over prolonged (84 hours) operation at 5.1 V.

Carbon Dots Synthesized from Cinchona Pubescens Vahl. An Efficient Antibacterial Nanomaterial and Bacterial Detector.

AbstractCarbon dots (CDs) synthesized using Cinchona pubescens Vahl from the hydrothermal method displayed blue emission radiation, pH dependency, homogeneous sizes, colloidal stability in water, and antibacterial features. They consist of graphene oxide and reduced graphene oxide, attributed to the antioxidant species extracted from the Cinchona pubescens Vahl that simultaneously synthesized and reduced graphene oxide. They reach a bacterial minimal inhibitory concentration of 62.5 μg mL−1 against Gram‐positive Staphylococcus aureus and Gram‐negative Pseudomonas aeruginosa strains, which is better than traditional antibiotics and other CDs obtained from similar natural sources and methods. The photoluminescent CDs were also used to detect bacteria, an essential application in microbiology, biotechnology, medical diagnosis, and food safety, showing the capability of distinguishing between gram‐positive and gram‐negative strains and between dead and alive gram‐positive bacteria. Thus, CDs obtained by green resources represent a promising platform to produce functional antibacterial agents and bacteria detectors.

Understorey light quality affects leaf pigments and leaf phenology in different plant functional types.

Forest understorey plants receive most sunlight in springtime before canopy closure, and in autumn following leaf‐fall. We hypothesised that plant species must adjust their phenological and photoprotective strategies in response to large changes in the spectral composition of the sunlight they receive. Here, we identified how plant species growing in northern deciduous and evergreen forest understoreys differ in their response to blue light and ultraviolet (UV) radiation according to their functional strategy. We installed filters in a forest understorey in southern Finland, to create the following treatments attenuating: UV radiation below 350 nm, all UV radiation (< 400 nm), all blue light and UV radiation (< 500 nm), and a transparent control. In eight species, representing different functional strategies, we assessed leaf optical properties, phenology, and epidermal flavonoid contents over two years. Blue light accelerated leaf senescence in all species measured in the understorey, apart from Quercus robur seedlings, whereas UV radiation only accelerated leaf senescence in Acer platanoides seedlings. More light‐demanding species accumulated flavonols in response to seasonal changes in light quality compared to shade‐tolerant and wintergreen species and were particularly responsive to blue light. Reduction of blue and UV radiation under shade reveals an important role for microclimatic effects on autumn phenology and leaf photoprotection. An extension of canopy cover under climate change, and its associated suppression of understorey blue light and UV radiation, may delay leaf senescence for understorey species with an autumn niche.

Effects of UV–visible radiation on growth, photosynthesis, pigment accumulation and UV-absorbing compounds in the red macroalga Gracilaria cornea (Gracilariales, Rhodophyta)

Radiation induces different processes in photosynthetic organisms through photosynthetic pigments and photoreceptors. This study evaluated the performance of the red alga Gracilaria cornea cultivated under different radiation treatments. The objective was to identify responses associated with the treatments and mediated by photoreceptors. For this, G. cornea was exposed for 15 days to low fluence radiation of the ultraviolet (UV)-visible spectrum (red, green and blue light, and UV-A and UV-B radiation) combined with a high fluence radiation provided by a low-pressure sodium lamp (SOX), in order to saturate the photosynthesis. We measure the growth rate and other variables, such as photosynthesis estimated as chlorophyll a fluorescence, chlorophyll a, phycobiliproteins, carotenoids, mycosporine-like amino acids (MAAs), phenolic compounds, antioxidant capacity soluble proteins, and internal carbon and nitrogen content. The results showed that the UV radiation influenced the growth rates, as well as the accumulation of internal compounds (carotenoids: violaxanthin, antheraxanthin and zeaxanthin; MAA palythine; and phenolic compounds). As the treatments with UV radiation also had a peak of blue light, the presence of photoreceptors sensitive to these qualities of radiation (UV-A, UV-B and blue light) is suggested. In general, UV-A appears to induce some compounds without affecting growth, while UV-B seems to cause the accumulation of compounds at the expense of growth. The effect of light quality on growth and metabolism in G. cornea is compared to that in other species following similar experimental design.

High efficiency green-emitting phosphor-in-glass films for high-power solid-state laser lighting

The next generation of solid-state lighting technology driven by laser diodes (LDs) is in full development, and the way green fluorescent materials with narrow-band emission (such as β-Sialon) exert their inherent potential in laser displays and projectors has attracted public interest. In this paper, stable borosilicate glass was utilized as an inorganic binder to prepare phosphor-in-glass films (PiFs) by cosintering sapphire and β-Sialon phosphor. There was no interface reaction between the glass and the phosphor, and the phosphor was uniformly and nondestructively distributed in the composite film closely attached to the sapphire. The optimized PiFs achieved an internal quantum efficiency of 76% and a thermal conductivity of 8.6 W m−1K−1, and a thermal diffusivity of 2.6 mm2 s−1 demonstrated their excellent thermal stability. A beam of high-purity light with a brightness of 887 lm and a luminous efficiency of 183 lm/W was achieved under 450 nm blue LD radiation, which is the relatively superior performance by β-Sialon series luminescent materials in an LD application reported thus far. We believe that in the near future, strategies such as adjusting glass composition, improving quantum efficiency, and sample postprocessing will further improve the performance of β-Sialon phosphors with narrow-band emission to make new contributions in the field of high-quality lasers.

Transcriptome Analysis Reveals Differences in Anthocyanin Accumulation in Cotton (Gossypium hirsutum L.) Induced by Red and Blue Light.

Many factors, including illumination, affect anthocyanin biosynthesis and accumulation in plants. light quality is the key factor affecting the process of photoinduced anthocyanin biosynthesis and accumulation. We observed that the red color of the Upland cotton accession Huiyuan with the R1 mutation turned to normal green color under light-emitting diodes (LEDs), which inspired us to investigate the effect of red and blue lights on the biosynthesis and accumulation of anthocyanins. We found that both red and blue lights elevated accumulation of anthocyanins. Comparative transcriptomic analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and GSEA, revealed that genes differentially expressed under different light conditions were enriched with the pathways of circadian rhythm, phenylpropanoid biosynthesis, anthocyanin biosynthesis, and flavone and flavonol biosynthesis. Not surprisingly, all the major structural genes related to biosynthesis of anthocyanins, including the key regulatory MYB transcription factor (GhPAP1D) and anthocyanin transporter (GhGSTF12), were induced by red or blue light treatment. However, LARs and MATEs related to biosynthesis of proanthocyanidins were more significantly up-regulated by red light radiation than by blue light radiation. Vice versa, the accumulation of anthocyanins under red light was not as high as that under blue light. In addition, we demonstrated a potential role of GhHY5, a key regulator in plant circadian rhythms, in regulation of anthocyanin accumulation, which could be achieved via interaction with GhPAP1D. Together, these results indicate different effect of red and blue lights on biosynthesis and accumulation of anthocyanins and a potential module including GhHY5 and GhPAP1D in regulation of anthocyanin accumulation in cotton. These results also suggest that the substrates responsible the synthesis of anthocyanins under blue light is diverted to biosynthesis of proanthocyanidin under red light.

The growth of Escherichia coli cultures under the influence of pheomelanin nanoparticles and a chelant agent in the presence of light.

Growing concern of antibiotic resistance has increased research efforts to find nonspecific treatments to inhibit pathogenic microorganisms. In this regard, photodynamic inactivation is a promising method. It is based on the excitation of a photosensitizer molecule (PS) with UV-Vis radiation to produce reactive oxygen species. The high reactivity of such species nearby the PS leads to oxidation of bacterial cell walls, lipid membranes (lipid peroxidation), enzymes, and nucleic acids, eventually producing cell death. In the last decade, many studies have been carried out with different photosensitizers to suppress the growth of bacteria, fungi, viruses, and malignant tumors. Here, our main motivation is to employ pheomelanin nanoparticles as sensitizers for inhibiting the growth of the Gram-negative bacteria E. coli, exposed to blue and UVA radiation. In order to perform our experiments, we synthesized pheomelanin nanoparticles from L-DOPA and L-cysteine through an oxidation process. We carried out experiments at different particle concentrations and different energy fluences. We found that cultures exposed to UVA at 166 μg/mL and 270 J/cm2, in conjunction with ethylenediaminetetraacetic acid (EDTA) as an enhancer, decreased in the viable count 5 log10. Different reactive oxygen species (singlet oxygen, hydroxyl radicals, and peroxynitrates) were detected using different procedures. Our results suggest that the method reported here is effective against E. coli, which could encourage further investigations in other type of bacteria.

Photostability of polylactide with respect to blue LED radiation at very high irradiance and ambient temperature

For an overall sustainable development of lighting systems, it is crucial to establish alternatives to fossil based optical plastics. One biodegradable plastic alternative, based exclusively on renewable raw materials and having outstanding optical properties, could be the bioplastic polylactide (PLA). In order to evaluate the stability of PLA under the influence of extreme levels of optical LED radiation (λmax = 450 nm, FWHM = 16.3 nm), aging experiments were carried out over a period of 5000 h (~ 7 months) using an innovative self-developed test setup. As a reference the widely used optical plastic polycarbonate (PC) was aged under the same conditions. The novel test setup allowed aging tests at low temperatures of 23.0 and 36.1 °C (below the crystallization temperature of PLA) with irradiances of 7.9 and 16.1 kW/m2, respectively. Photodegradation tests in which temperature can be varied virtually independent of radiant flux were performed. To the best of our knowledge this is a first in degradation experiments. By this, aging can be attributed to more radiation- or temperature-related phenomena. Before, during, and after aging, optical, mechanical and chromatographic methods were used to analyze the samples. PLA was found to be largely resistant to visible blue LED radiation under the selected aging conditions. Only an increase in surface hardness and stiffness, indicating embrittlement, was observed. In contrast, even at the low temperatures used in these experiments, PC shows a significant decrease in transmission in the short-wavelength range of up to 17.0% after prolonged aging. Moreover, known degradation products (by FTIR spectroscopy), a decrease in molar mass (5.1%) and a trend increase in Martens hardness and indentation modulus, were detected for all PC of samples.

Deterioration of Bismuth-Doped fiber lasers performance induced by blue and green laser light launched into cladding

For the first time, we demonstrate the photobleaching process of bismuth-related active centers (BACs) induced by blue and green laser radiation launched into the cladding of an active fiber having the low-refractive index polymer coating. The changes in small-signal loss spectra of the exposed Bi-doped fibers are presented and analyzed. Temporal evolution of luminescence intensity of BACs is measured for different powers of bleaching light. The effect of bleaching on Bi-doped fiber laser characteristics was studied. It was found that time-to-destruction of Bi-doped fiber laser varies in dependence on the power and wavelength of the used bleaching light. In particular, the blue laser radiation launched into the active fiber cladding for a timespan of almost 10 sec can completely disable the operation of a bismuth laser at 1.71 µm. We estimated the efficiency of bleaching process in Bi-doped fiber under blue laser irradiation.

Disinfection of water by using laser radiation

The use of high-power laser radiation in water is not common. A major reason for this is the high absorption in water above 550 nm and the resulting higher requirement for laser power. Due to the progressive developments in laser technology in the range of blue radiation with more powerful laser sources, new areas of application with high power requirements can be developed. An application for water treatment using laser radiation is unknown but has a high potential due to the high energy density that can be generated by laser radiation. In this work, seawater from the North Sea was disinfected using laser radiation. A laser with wavelengths of 448 nm and a power of 1400 W was used. The water was irradiated statically in a cuvette (water volume of 20.67 ml).

EGR1 Is a Critical Gene in Response of Human Keratinocyte to Blue Light Radiation.

Introduction: Investigating the molecular mechanism of cellular response to light radiation has attracted many researchers' attention. In the present study, the critically affected gene by 7.5 min blue light radiation in human keratinocytes was investigated via network analysis. Methods: Gene expression profiles of human keratinocytes exposed to 7.5 min blue light radiation plus controls were extracted from Gene Expression Omnibus (GEO). The significant dysregulated genes plus 100 first neighbors were investigated by Cytoscape software and its applications. The central nodes of the network based on four centrality parameters were determined and discussed. Results: Among 6 significant dysregulated genes, 4 individuals were recognized by the STRING database. The network was constructed by using the 4 queried genes and 100 first neighbors. EGR1, STAT1, and ISG15 were identified as central nodes; however, the prominent role of EGR1 was highlighted. Conclusion: EGR1 appeared as a critically affected gene after blue light irradiation. It seems that this upregulated gene is responsible for protecting human keratinocytes against stress and cancer. Therefore, the application of blue light may be accompanied by antistress effects in the human body.

Review of Low-Frequency Noise Properties of High-Power White LEDs during Long-Term Aging.

Low-frequency noise investigation is a highly sensitive and very informative method for characterization of white nitride-based light-emitting diodes (LEDs) as well as for the evaluation of their degradation. We present a review of quality and reliability investigations of high-power (1 W and 3 W) white light-emitting diodes during long-term aging at the maximum permissible forward current at room temperature. The research was centered on the investigation of blue InGaN and AlInGaN quantum wells (QWs) LEDs covered by a YAG:Ce3+ phosphor layer for white light emission. The current-voltage, light output power, and low-frequency noise characteristics were measured. A broadband silicon photodetector and two-color (blue and red) selective silicon photodetectors were used for the LED output power detection, which makes it possible to separate physical processes related to the initial blue light radiation and the phosphor luminescence. Particular attention was paid to the measurement and interpretation of the simultaneous cross-correlation coefficient between electrical and optical fluctuations. The presented method enables to determine which part of fluctuations originates in the quantum well layer of the LED. The technique using the two-color selective photodetector enables investigation of changes in the noise properties of the main blue light source and the phosphor layer during the long-term aging.

Initiation of lightning flashes simultaneously observed from space and the ground: Narrow bipolar events

We investigate the initiation of four lightning flashes detected from ground by means of the Colombia Lightning Mapping Array (Colombia-LMA) and simultaneously observed from space by the optical sensors of the Atmosphere-Space Interactions Monitor (ASIM) on board the International Space Station (ISS), the Geostationary Lightning Mapper (GLM), and the Lightning Imaging Sensor on the ISS. The initiations of the flashes are characterized by isolated and predominant optical blue pulses (337.0 nm). In three of the flashes, red emissions (777.4 nm), a dominant line of hot lightning, were not detected during their initiation. In these cases, the initiations were also accompanied by bipolar VLF/LF waveform with a narrow short duration (<40 μs) and VHF emissions with high radio frequency power (<269 kW). The detection of the blue emissions without any red luminosity supports that the fast breakdown processes at the flash initiation can be exclusively of streamer nature. The onset of the fourth flash was associated with both blue and red radiation, and with weak narrow bipolar waveform in VLF/LF and low VHF power. The flashes initiated between the midlevel negative and upper positive charge regions. This paper presents and discusses the first fast breakdown processes observed simultaneously from ground by means a Lightning Mapping Array (LMA) and from space during the onset of lightning flashes.

РОЗРОБКА НЕДОПОВАНОЇ ОРГАНІЧНОЇ СВІТЛОВИПРОМІНЮВАЛЬНОЇ СТРУКТУРИ ІЗ ЕМІСІЄЮ У ТЕМНО-СИНЬОМУ ДІАПАЗОНІ НА ОСНОВІ ДОНОРНО-АКЦЕПТОРНОГО МАТЕРІАЛУ КАРБАЗОЛОТЕТРАХЛОРОПІРИДИНУ

The development of efficient organic light emitting diodes (OLED) based on the phenomenon of intramolecular thermally activated delayed fluorescence (TADF), in the design of which there are no blue phosphorescent emitters based on rare earth metals, still remains a challenge in the development of new lighting systems and OLED displays. The article proposes a technological approach to the formation of new type of OLED, where the emitter is an organic donor-acceptor molecular material 9- (2,3,5,6-tetrachloropyridin-4-yl) -9H-carbazole (4-CzPyCl4), in which electronic interaction between the donor and acceptor fragment plays a key role in the mechanism of delayed fluorescence. The design of the developed light-emitting heterostructure uses layer-by-layer formation of functional nanosized organic films, in contrast to traditional OLED designs of dark blue color radiation, which uses a guest-host systemThe external quantum efficiency of the developed OLED is 2.8%. The maximum brightness of 3,000 cd/m2 is reached at a voltage of 15 V. The chromaticity coordinates CIE (x, y) 1931 are (0.15, 0.13), which corresponds to the “dark blue” emitting spectral zone.

ST. JOHN'S WORT (HYPERICUM PERFORATUM L.) FLOWER BASED CARBON/GRAPHENE QUANTUM DOT STRUCTURE PRODUCTION AND CHARACTERIZATION FOR BIOIMAGING AND DRUG DELIVERY SYSTEMS

In this study, it was aimed to obtain carbon and graphene quantum dot structures from St. John's Wort (Hypericum perforatum L.) flowers, originating from the city of Hatay. Hypericum perforatum L. flower sample was subjected to carbonization at different temperatures such as 200, 225 and 250 ℃ for the desired quantum dot structure yields. It has been observed that the best radiation after carbonization is at 250 ℃. Fourier transform infrared spectrometer, X-ray diffraction and scanning electron microscopy techniques were used to determine the structural characterizations and surface morphology, respectively. The UV radiation of Hypericum perforatum L. flower-based carbon and graphene quantum structures was followed at 365 nm and the blue glow was observed very clearly. With this study, quantum and graphene dot structures based on Hypericum perforatum L. flower have been introduced to the literature for the first time. In addition, the quantum dot structures with blue radiation obtained within the scope of the study will be an alternative reference for many bioimaging and drug delivery system studies.

Phenylene Bis-Diphenyltriazine (TriAsorB), a new sunfilter protecting the skin against both UVB + UVA and blue light radiations.

Sunlight induces actinic keratosis, skin cancers and photoaging. Photoprotection is thus a major issue in public health to prevent the harmful effects of solar ultraviolet (UV) radiations. Recent data have shown that the visible (VIS) and infrared (IR) radiations can lead to skin damage by oxidative stress, suggesting that a balanced protection across the entire spectrum of sunlight is necessary to prevent cutaneous alterations. In this context, we developed a new generation of sunfilter called Phenylene Bis-Diphenyltriazine or TriAsorB (CAS N°55514-22-2). The aim of the present study was to assess the photoprotective efficacy of TriAsorB from UV to IR light. Spectrophotometric assays were performed to measure absorption and reflectance of TriAsorB in the different spectral ranges of sunlight: UV, VIS including blue light or high energy visible (HEV) and IR. DNA damage was evaluated using reconstructed human epidermis (RHE): 8-hydroxy-2'-deoxyguanosine (8OHdG) in response to HEV exposure, pyrimidine dimers (CPDs) and (6-4) photoproducts following solar-simulated radiation (SSR). TriAsorB is a broad spectrum UVB + UVA filter including long UVA. Interestingly, it also absorbs VIS radiations, especially in the HEV region. These radiations are also reflected. Protection in the IR spectral range is weak. Furthermore, the sunfilter specifically protects the skin against the oxidative lesions 8OHdG induced by HEV and prevents SSR-induced DNA damage. Thus, TriAsorB is an innovative sunfilter that might be used in sun care products for skin photoprotection from UV to VIS radiations. Finally, it prevents sunlight genotoxicity and protected the skin against solar radiations, especially blue light.

Flame characteristics of a high-pressure LOX/H2 rocket combustor with large optical access

Hot fire tests were performed with a newly developed single-injector research combustor featuring a large optical access (255 × 38 mm) for flame imaging. Within these tests the propellant combination of liquid oxygen and cold gaseous hydrogen (LOX/H2) has been used at chamber pressures up to 70 bar and ratios of oxidizer to fuel (ROF) at the main injector of 3.4–6. The large optical access enabled synchronized flame imaging using OH* and blue radiation wavelengths covering an area of the combustion chamber from the injection plane to shortly before the contraction section of the nozzle. High-speed flame imaging was realized for three different operating conditions. Combined with data from temperature, pressure and unsteady pressure sensors high-quality validation data for numerical modeling has been gained. Several key dimensions of the flame topology were extracted from the imaging. The change in flame topology in response to different operating conditions is consistent with expectations from the literature, in particular the dependence of flame opening angle on injection momentum flux ratio. Using OH* imaging for such topology measurements was found to have less uncertainty than with blue radiation imaging.

The Effect of Blue Light Source in a Lighting Installations on Human Circadian Rhythms

This article describes effect of the blue light on a human health. This effect is emmiting by electrical devices and has a negative impact on person, even if it does not fall into your eyes. This work consists on comparison study of blue radiation spectrum and impact on human organism. It helps to define permissible level of energy dependence on light radiation. The conception of biological impact connected with melanopsin, which one has rods and cones. For humans, nonvisual biological effects, which can be parameterized by the circadian action factor (CAF), are important for their health and work performance. When we spend a lot of time in front of screens of devices, we are receiving radiation of blue light. The article analyses questions associated with biological exposure to radiation from some light emitting diode and lamp light sources with various radiation spectrum (correlated colour temperature Tcc). The biological exposure concept is connected with melanopsyn containing receptors on the eye retina, signals from which arrive to epiphysis and control concentration of the hormone melatonin in the blood. Circadian rhythms are seen at every level of biology, from single cells to complex behaviors. The timing of every biological function in mammals is governed by the master clock in the suprachiasmatic nuclei (SCN), which has an intrinsic period of slightly longer than 24 hours. The light/dark pattern incident on the retina synchronizes the SCN to the 24-hour local time, coordinating and enabling diverse biological functions to occur at the correct time of day and night for optimum species survival. A wide range of modern maladies, from sleep disorders to cancer, has been linked to light-induced circadian disruption. Light has, however, been defined only in terms of the human visual system, not the circadian system. Light source and systems development should consider the needs of both the visual and non-visual systems. Certain signals are fulfil function of controlling the concentration chromatophorotropic hormone within blood. As a basis for calculation were included photochemical and electrical processes in amphiblestrodes, physiological human parameters, as well as coefficient of circadian efficiency, coefficient of growth-inhibitory activity of melatonin and biological equivalent. The optical information is essential for physiological systems of humans, because it not only provides the visual information but also affects their physical, physiological, and psychological behaviors, in which researchers call the latter “non-visual biological effects of light”. In the evolution of lives on earth, the sun and its spectrum, and the alternation of day and night play an important role in the adaptation of human to the natural environment. As receptors of light, human eyes are deeply influenced by standard light, to which the structure and function of human eyes are developed more accustomed during the long-term daily work.