Red Photons Research Articles

PC12 differentiation to neuron cells activated by a low-level laser at 660 nm on UV pre-treated CR-39 scaffolds with parallel microchannels.

The lack of regeneration of injured neurons in the central and peripheral neural system leads to the failure of damaged tissue repair in patients. While there is no definitive cure for most neurodegenerative diseases, new therapeutic methods that cause the proliferation and differentiation of neurons are of interest. Challenges such as the inability of neuronal cells to proliferate after injury, the lack of a stimulus for initial stimulation, and the presence of the microenvironment around CNS neurons contain several inhibitory factors that prevent neuron regeneration, thus, creating a structure similar to the extracellular matrix helps the cell proliferation in current treatment. A rapid method of neuron-like cell differentiation of PC12 cells is introduced here based on a novel synthetic scaffold. Initially, poly allyldiglycol carbonate (CR-39) substrate is textured under a high dose of ArF UV excimer laser (1000 shot, 300 mJ/pulse equivalent to 300 J/cm2 at 193 nm) to create superficial periodic parallel microchannels with the micrometer spacing and sub-micron width. Ultraviolet treated CR-39 (UT CR-39) provides a suitable scaffold to speed up the transformation/differentiation of PC12 cells. The latter is pheochromocytoma of the rat adrenal medulla as an embryonic origin from the neural crest usually exposed to the nerve growth factor (NGF). In fact, PC12 cells are seeded on the microchannels and simultaneously are stimulated by coherent red photons at 660 nm within the therapeutic window. The UT CR-39 scaffold undergoes extra improvement of ∼ 30% after 12 minutes of laser activation regarding the photo-biomodulation (PBM) mechanism. The cell activation due to the coherent photons also gives rise to enhanced proliferation/differentiation. Here, PC12 cells are efficiently differentiated into neurons according to immunocytochemistry (ICC) and Western Blot verification tests based on MAP2 and synapsin-1 protein expression. In general, UT CR-39 acts as a superior bed to elevate the population of neuron-like cells up to threefold against those of untreated (control)ones. We conclude that the surface cross-linking due to UV exposure and subsequent induced hydrophilicity notably contribute to the neuron-like cell differentiation of PC12 without adding NGF.

Temporal Separation of Red and Blue Photons Does Not Increase Photon Capture or Yield of Lettuce

Temporal separation of red (R) and blue (B) (alternating R/B) photons has been reported to increase leaf area, photon capture, and yield of lettuce compared with delivering both colors together (concurrent R+B). We grew three diverse lettuce cultivars (Grand Rapids, Rex, and Red Sails) under concurrent R+B photons (9/1 ratio) and alternating R/B photons (9/1 ratio) under an equal daily light integral (DLI) of either 8.6 or 23 mol⋅m−2⋅d−1. Contrary to five previous studies, we found no increase in either leaf area or fresh mass and dry mass in any of the alternating R/B photon treatments compared with concurrent R+B photons. In fact, at a DLI at 8.6 mol⋅m−2⋅d−1, alternating R/B photons decreased the dry mass of ‘Grand Rapids’ and ‘Rex’ lettuce by 38% and 17%, respectively. Two previous studies reported that photosynthetic rates increased with alternating R/B photons; however, we found that the net assimilation rate was generally decreased by alternating R/B photons. An analysis of images obtained from automated digital photography revealed that the relative expansion rate of leaves was 61% higher during intervals of pure B rather than intervals of pure R photons at the same photosynthetic photon flux density; however, this did not result in a higher leaf area compared with concurrent R+B photons. Overall, our studies do not indicate that alternating R/B photons increase lettuce leaf area or yield compared with concurrent R+B photons.

A Methylene Blue/Sodium Sulfinate Photo‐Initiating System for the Red‐Light Emulsion Photopolymerization of Methyl Methacrylate

AbstractThe emulsion photopolymerization of methyl methacrylate (MMA) using red light is reported. The synthesis of poly(methyl methacrylate) (PMMA) latexes is initiated by irradiation of a new, very efficient red‐absorbing methylene blue (MB)/sodium para‐toluenesulfinate (NapTS) system in the red region (660 nm). Visible, and especially red light penetrates the dispersed medium imposed by the emulsion process better than ultra‐violet photons (UVs). However, emulsion photopolymerizations require the development of fully water‐soluble initiating systems activable by red light, which is still hugely challenging because red photons are much less energetic, therefore generally lead to less efficient photochemical processes. The influence of the surfactant concentration and the solids content is examined over particle sizes and polymerization kinetics. The polymerizations work for solids contents between 10 and 25 wt%, with narrowly distributed particles of average sizes ranging from 40 to 65 nm. Calculations of Mie scattering support the observation that at a given wavelength the larger the particles the lower the penetration. All latexes obtained are slightly blue, which are traced to the regeneration of MB when the latexes are exposed to dioxygen. The dye regeneration enables the reactivation of the photopolymerization process.

B-Box transcription factor BBX28 requires CONSTITUTIVE PHOTOMORPHOGENESIS1 to induce shade-avoidance response in Arabidopsis thaliana.

Shade avoidance syndrome is an important adaptive strategy. Under shade, major transcriptional rearrangements underlie the reallocation of resources to elongate vegetative structures and redefine the plant architecture to compete for photosynthesis. BBX28 is a B-box transcription factor involved in seedling de-etiolation and flowering in Arabidopsis (Arabidopsis thaliana), but its function in shade-avoidance response is completely unknown. Here, we studied the function of BBX28 using two mutant and two transgenic lines of Arabidopsis exposed to white light and simulated shade conditions. We found that BBX28 promotes hypocotyl growth under shade through the phytochrome system by perceiving the reduction of red photons but not the reduction of photosynthetically active radiation or blue photons. We demonstrated that hypocotyl growth under shade is sustained by the protein accumulation of BBX28 in the nuclei in a CONSTITUTIVE PHOTOMORPHOGENESIS1 (COP1)-dependent manner at the end of the photoperiod. BBX28 up-regulates the expression of transcription factor- and auxin-related genes, thereby promoting hypocotyl growth under prolonged shade. Overall, our results suggest the role of BBX28 in COP1 signaling to sustain the shade-avoidance response and extend the well-known participation of other members of BBX transcription factors for fine-tuning plant growth under shade.

Two-photon Absorption and Photoionization of a Bacterial Phytochrome

Phytochromes constitute a family of photosensory proteins that are utilized by various organisms to regulate several physiological processes. Phytochromes bind a bilin pigment that switches its isomeric state upon absorption of red or far-red photons, resulting in protein conformational changes that are sensed by the organism. Previously, the ultrafast dynamics in bacterial phytochrome was resolved to atomic resolution by time-resolved serial femtosecond X-ray diffraction (TR-SFX), showing extensive changes in its molecular conformation at 1 picosecond delay time. However, the large excitation fluence of mJ/mm2 used in TR-SFX questions the validity of the observed dynamics. In this work, we present an excitation-dependent ultrafast transient absorption study to test the response of a related bacterial phytochrome to excitation fluence. We observe excitation power-dependent sub-picosecond dynamics, assigned to the population of high-lying excited state Sn through resonantly enhanced two-photon absorption, followed by rapid internal conversion to the low-lying S1 state. Inspection of the long-lived spectrum under high fluence shows that in addition to the primary intermediate Lumi-R, spectroscopic signatures of solvated electrons and ionized chromophore radicals are observed. Supported by numerical modelling, we propose that under excitation fluences of tens of μJ/mm2 and higher, bacterial phytochrome partly undergoes photoionization from the Sn state in competition with internal conversion to the S1 state in 300 fs. We suggest that the extensive structural changes of related, shorter bacterial phytochrome, lacking the PHY domain, resolved from TR-SFX may have been affected by the ionized species. We propose approaches to minimize the two-photon absorption process by tuning the excitation spectrum away from the S1 absorption or using phytochromes exhibiting minimized or shifted S1 absorption.

Far-red Photons Increase Light Capture but Have Lower Photosynthetic Capacity Than Red Photons

Far-red photons (700–750 nm) can accelerate crop growth during indoor production through both physiological and morphological processes. A previous study showed that far-red photons can drive photosynthesis with efficiency similar to that of traditionally defined photosynthetically active photons (400–700 nm) if they are provided together with shorter-wavelength photons. Far-red photons also promote leaf and canopy expansion, which can increase light interception and growth. This study aimed to distinguish the contribution of morphological and physiological changes to crop growth induced by substituting red photons with far-red photons. We studied the long-term effects of substituting red photons with far-red photons on canopy light interception and whole-plant photosynthesis. ‘Little Gem’ lettuce (Lactuca sativa) seedlings were grown under four light spectrums of the same total photon flux density (400–750 nm). In addition to a background of a mixture of white and blue photons of 150 μmol⋅m−2⋅s−1, we provided 51 μmol⋅m−2⋅s−1 red photons, far-red photons, or mixtures of red and far-red photons. In the first run, plants were harvested twice. The first harvest was at canopy closure, and the second harvest was when plants reached full size. In the second run, we harvested lettuce plants more frequently to minimize leaf overlap and interplant competition. We found that far-red photon substitution promoted leaf and canopy expansion and increased light interception. The effect of far-red photon substitution on leaf and canopy expansion was stronger in the second run than in the first run, likely because of lower plant density in the second run when plants were harvested more frequently. Far-red photon substitution of red photons decreased the amount of extended photosynthetically active radiation (ePAR) photons (400–750 nm) absorbed by leaves because of the lower leaf absorptance of far-red photons. The greater effect on canopy expansion in the second run of far-red photons substitution was able to exceed the reduction of ePAR photon absorption by leaves; therefore, we observed an increased crop gross photosynthetic rate (Pg) between the second and third harvests during the second run. However, during the first run, lower absorptance of ePAR completely offset the effect of the greater canopy size and light interception, and crop Pg was decreased in the first run before the first harvest. The changes in light interception and crop Pg resulting from far-red photon substitution did not affect dry weight. Far-red photons had photosynthetic activity when applied with a blue and white light mixture, but their efficiency was approximately half that of red photons, potentially because of the lower absorptance of far-red photons. In conclusion, far-red photon substitution of red photons increased canopy size but decreased ePAR photons absorbed by leaves and did not increase the final dry weight. Because far-red light-emitting diodes (LEDs) have higher efficacy for converting electricity into photons, including far-red LEDs in fixtures for sole-source lighting can reduce energy costs without decreasing lettuce yields.

Physical vapor deposition of Yb-doped CsPbCl3 thin films for quantum cutting

Ytterbium-doped CsPbCl${}_{3}$ emerges as the primary contender for a quantum cutting coating on silicon solar cells, aiming to enhance both their efficiencies and durability. This is accomplished by converting each incident ultraviolet and blue photon with energies greater than 2.5 eV into two 1.25 eV near-infrared red photons. The potential of this approach lies in the possibility of surpassing the Quessier limit, thereby augmenting the efficiencies of silicon solar cells. While thin films produced through colloidal synthesis and nanocrystal dispersions have demonstrated photoluminescence quantum yields nearing 200%, there has been a growing interest in employing physical vapor deposition as a large-area scalable method due to sub-band gap absorption exhibited by colloidal films. In the present study, the authors made an intriguing discovery regarding the significant influence of post-deposition annealing environment and protocols on the near-infrared photoluminescence quantum yields in Yb-doped halide perovskite films that demonstrate the downconversion of ultraviolet and blue light through quantum cutting.

Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile

The realization of microscopic heat engines has gained a surge of research interest in statistical physics, soft matter, and biological physics. A typical microscopic heat engine employs a colloidal particle trapped in a confining potential, which is modulated in time to mimic the cycle operations. Here, we use a lanthanide-doped upconverting particle (UCP) suspended in a passive aqueous bath, which is highly absorptive at 975 nm and converts near infra red (NIR) photons to visible, as the working substance of the engine. When a single UCP is optically trapped with a 975 nm laser, it behaves like an active particle by executing motion subjected to an asymmetric temperature profile along the direction of propagation of the laser. The strong absorption of 975 nm light by the particle introduces a temperature gradient and results in significant thermophoretic diffusion along the temperature gradient. However, the activity of the particle vanishes when the trapping wavelength is switched to 1064 nm. We carefully regulate the wavelength-dependent activity of the particle to engineer all four cycles of a Stirling engine by using a combination of 1064 nm and 975 nm wavelengths. Since the motion of the particle is stochastic, the work done on the particle due to the stiffness modulation per cycle is random. We provide statistical estimation for this work averaged over five cycles which can be extended towards several cycles to make a Stirling engine. Our experiment proposes a robust set-up to systematically harness temperature which is a crucial factor behind building microscopic engines.

Charge relaxation associated with photon-induced deactivation of various traps in MAPbI3 films

Photon-induced deactivation of traps in MAPbI3 can strongly affect charge relaxation behavior. Charge relaxation associated with photo-induced deactivation of various traps in MAPbI3 films was investigated through steady-state and time-resolved photoluminescence (PL) spectroscopy under laser excitation at 635 and 430 nm to investigate the properties of the traps. Three types of traps that could be deactivated by photons were observed in the MAPbI3 films, namely TL, TH, and TGB. TL and TH, which were related to MAPbI3 bulk, had low and high photon energy thresholds (red and blue photons) for deactivation, respectively. TGB was related to the traps at grain boundaries in MAPbI3 and had a low photon energy threshold (red photons) for deactivation. The energy level of TGB was higher than that of the conduction band of MAPbI3. Under blue excitation, TGB mediated a fast nonradiative recombination at few nanoseconds, and TL and TH mediated a slow nonradiative recombination at few 100 ns. The fast nonradiative recombination led to a significantly low initial normalized photoluminescence quantum yield (PLQY) (1/22) under blue excitation, compared with that obtained under red excitation (1/4). The deactivation of TL and TH resulted in increases in both the amplitude of PL and recombination time. The deactivation of TGB resulted only in a significant increase in PLQY of blue excitation.

Latest Advances in Narrow‐Band Phosphors and Their Role in Color Management

Latest Advances in Narrow‐Band Phosphors and Their Role in Color Management

Temperature and Light Spectrum Differently Affect Growth, Morphology, and Leaf Mineral Content of Two Indoor-Grown Leafy Vegetables

This study was carried out to determine the effect of three commercial LEDs of different spectra with or without far red (FR) photons on the growth, morphology, and mineral content of two leafy vegetables under two temperatures (30 °C and 21 °C). The two leafy greens were ‘Cegolaine’ lettuce (Lactuca sativa) and ‘Petite Star’ pak choy (Brassica rapa subsp. Chinensis). In each temperature, there were three light spectra: red and blue LED, and white LED with or without FR. All spectra of lights were adjusted to a total photon flux density of 250 μmol m−2 s−1 at the top of the plant canopy. Results indicated that temperature treatment had a significant influence on most measured parameters. When temperature increased from 21 to 30 °C, lettuce shoot fresh and dry weights increased by 30% and 53%, respectively, while those of pak choy increased by approximately 22%. For both species, plants at high temperature had a larger leaf area but lower mineral content compared to those at low temperature. The spectrum treatment had a minor or no effect on the measured traits. In conclusion, the 5% FR did not impact the yield or biomass of either crop and the plant responses to spectra varied with temperature and species. The two temperatures resulted in significant differences in growth, morphology, and leaf mineral content in both species.

Real-Time Visualization of Photobrightening in Lead Halide Perovskites Using Confocal Laser Scanning Microscopy

Light induced changes in the optoelectronic properties affect the performance and the stability of halide perovskites. In this work, we report the real-time visualization of the photobrightening (PLB) effect using confocal laser scanning microscopy wherein the photon induced enhancement in photoluminescence is observed and their role in conductivity and photovoltaic properties are studied. The methodology is inspired from the Fluorescence Recovery After Photobleaching (FRAP) technique that is traditionally used to study biological cells. The role of composition, and surface/grain boundaries of perovskites, wavelengths, and intensity of illuminating photons, and time of illumination on the photobrightening or photobleaching is thoroughly investigated. The CH3NH3PbI3 exhibits a dominant photobrightening effect, with green photons showing more PLB than blue or red photons. The study of PLB between films and single crystals clearly shows the effect is a surface phenomenon. The presence of mixed iodide/bromide or pure bromide in the halide site and formamidinium or cesium in the A site suppressed the PLB. The strain relaxation in the organic site is found to be responsible for the PLB effect, and it enhanced the overall conductivity in material leading to better photovoltaic performance.

Sensitizer-controlled photochemical reactivity via upconversion of red light.

By combining the energy input from two red photons, chemical reactions that would normally require blue or ultraviolet irradiation become accessible. Key advantages of this biphotonic excitation strategy are that red light usually penetrates deeper into complex reaction mixtures and causes less photo-damage than direct illumination in the blue or ultraviolet. Here, we demonstrate that the primary light-absorber of a dual photocatalytic system comprised of a transition metal-based photosensitizer and an organic co-catalyst can completely alter the reaction outcome. Photochemical reductions are achieved with a copper(i) complex in the presence of a sacrificial electron donor, whereas oxidative substrate activation occurs with an osmium(ii) photosensitizer. Based on time-resolved laser spectroscopy, this changeover in photochemical reactivity is due to different underlying biphotonic mechanisms. Following triplet energy transfer from the osmium(ii) photosensitizer to 9,10-dicyanoanthracene (DCA) and subsequent triplet-triplet annihilation upconversion, the fluorescent singlet excited state of DCA triggers oxidative substrate activation, which initiates the cis to trans isomerization of an olefin, a [2 + 2] cycloaddition, an aryl ether to ester rearrangement, and a Newman-Kwart rearrangement. This oxidative substrate activation stands in contrast to the reactivity with a copper(i) photosensitizer, where photoinduced electron transfer generates the DCA radical anion, which upon further excitation triggers reductive dehalogenations and detosylations. Our study provides the proof-of-concept for controlling the outcome of a red-light driven biphotonic reaction by altering the photosensitizer, and this seems relevant in the greater context of tailoring photochemical reactivities.

In Situ IGZO/ZnON Phototransistor Free of Persistent Photoconductivity with Enlarged Spectral Responses

We present comprehensive studies on ZnON thin films deposited by radio-frequency (RF) magnetron sputtering using a ZnO target under various nitrogen plasma conditions. A ZnON thin film grown under the highest nitrogen partial flow rate exhibits the lowest optical bandgap of 1.84 eV, excellent stability upon air exposure, an amorphous/nanocrystalline structure, and the strongest stoichiometric Zn3N2 chemical states. The highest field-effect mobility of 4.28 cm2 V–1 s–1, the largest responsivity, and the negligible persistent photoconductivity (PPC) effect against visible light are also realized by the thin-film transistor (TFT) configuration. The device performance of the ZnON phototransistor is compared to those of other oxide semiconductors of ZnO and InGaZnO (IGZO). Finally, an IGZO/ZnON phototransistor, where ZnON was deposited on top of IGZO by an in situ process, demonstrates high specific detectivities (1.65 × 1013, 1.35 × 1013, and 2.0 × 1014 Jones against red, green, and blue photons, respectively) without the PPC effect. We examined the photoluminescence (PL) spectra of ZnON with respect to nitrogen-associated defects, which are yet to be discussed, and emphasize that our optimum deposition process is free of the poisoning effect. To our knowledge, this is the first report on a ZnON phototransistor in which the channel was prepared by reactive sputtering of a ZnO target.

On the pros and cons of red photons for greenhouse tomato production: increasing the percentage of red photons improves LED efficacy but plant responses are cultivar-specific

ABSTRACT Supplemental lighting is necessary for winter greenhouse tomato production, and optimised spectra must consider both yield and energy use. In a 20-week winter greenhouse experiment, two common commercial tomato cultivars – ‘Merlice’ and ‘Brioso’ – were grown under four LED spectra with 38%, 63%, 81%, and 95% red photons. As the percentage of red photons increased, the blue and green percentages decreased (not at the same ratio). Stem length, specific leaf area, and dry mass partitioning were not significantly affected by spectra in either cultivar, but increasing the red percentage from 38% to 95% decreased harvested fruit fresh mass by 13%, total plant dry mass by 7.1%, and fruit dry mass by 9.5% in ‘Merlice’. There were no significant differences in these parameters for ‘Brioso’. The yield kWh−1 increased with increasing percent red in both cultivars because LED fixtures with higher fractions of photons from 660 nm red LEDs have higher photon efficacies (µmol J−1). The efficacies of the lamps in this study were estimated to range from 2.6 to 3.6 µmol J−1. Growers must consider tradeoffs that can occur between yield and efficacy in some cultivars, and how these factors apply to their situation, when choosing the spectrum for their greenhouse.

New Experiment Demonstrates Transformation of Visible Photons into Other Visible Photons with Different Energy and Momentum

A new experiment demonstrates that although mixed red and green wavelength photons may be perceived by the human eye as yellow, actual yellow wavelength photons are also produced. The experiment is easily repeatable and provides a basis for additional experimentation. The results raise a question as to the accuracy of element percentage predictions based on the intensity of spectrum lines. Other experiments with results supporting the transformation of photons with a given wavelength to photons with a different wavelength, such as the Compton Effect, are discussed. Also, Markarian 501 along with other Gamma-Ray Burst (GRB) data are shown to perhaps be the first evidence that photons, like other particles, do not all travel at the same speed in a vacuum. If true, then photons can be treated as other quantum objects whose wavelengths are associated with both rest mass and speed. This possibility provided the motivation to conduct the new experiment.

Stimulated Raman generation of aqueous singlet oxygen without photosensitizers.

Singlet oxygen is traditionally produced via photosensitizer molecules such as methylene blue, which function as catalysts. Here we investigate stimulated Raman generation of singlet oxygen from dissolved oxygen in both water (H2O) and heavy water (D2O) using nanosecond-pulsed visible blue laser light in the 400-440nm spectral region without singlet oxygen photosensitizers. We report an oxygen-dependent Stokes peak in the red spectrum (600-670nm) that is identical when produced in H2O and D2O. These red Stokes photons are not detected when an oxygen quencher is present. Temporal photodepletion of the uric acid absorbance peak at 294nm is consistent with singlet oxygen generation. We postulate that a two-photon stimulated Raman process produces singlet oxygen from O2 dissolved within the solvents. We note that the energy difference between input and output photons of 0.97eV is precisely the energy needed to excite O2 to its singlet state.

Blue and red upconversion color tuning of Tm3+ via pulse excitation based on the thermal effect.

Color-tunable upconversion luminescence has wide prospects for anti-counterfeiting and disease diagnosis/treatment. To date, achieving high-quality tunable red and blue emissions using a single excitation wavelength remains a formidable challenge, due to the large energy difference between the red and blue photons. In this Letter, based on Tm3+ upconversion luminescence, blue dominant and red dominant emissions are generated upon 980-nm excitations using a short and long pulse, respectively. The corresponding color tuning mechanisms are investigated based on the spectral observations. The proposed color tuning strategy is particularly useful for in vivo applications as the red and blue lights play important roles in biological imaging and drug release, respectively.

A Chloroplast-Localised Fluorescent Protein Enhances the Photosynthetic Action Spectrum in Green Algae

Green microalgae are important sources of natural products and are attractive cell factories for manufacturing high-value products such as recombinant proteins. Increasing scales of production must address the bottleneck of providing sufficient light energy for photosynthesis. Enhancing the photosynthetic action spectrum of green algae to improve the utilisation of yellow light would provide additional light energy for photosynthesis. Here, we evaluated the Katushka fluorescent protein, which converts yellow photons to red photons, to drive photosynthesis and growth when expressed in Chlamydomonas reinhardtii chloroplasts. Transplastomic algae expressing a codon-optimised Katushka gene accumulated the active Katushka protein, which was detected by excitation with yellow light. Removal of chlorophyll from cells, which captures red photons, led to increased Katushka fluorescence. In yellow light, emission of red photons by fluorescent Katushka increased oxygen evolution and photosynthetic growth. Utilisation of yellow photons increased photosynthetic growth of transplastomic cells expressing Katushka in light deficient in red photons. These results showed that Katushka was a simple and effective yellow light-capturing device that enhanced the photosynthetic action spectrum of C. reinhardtii.

Plant Photochemistry under Glass Coated with Upconversion Luminescent Film

It has been shown that the cultivation of plants under glass coated with nano-sized upconversion luminophores led to an increase in plant productivity and the acceleration of plant adaptation to ultraviolet radiation. In the present work, we examined the effect of upconversion nanopowders with the nominal composition Sr0.955Yb0.020Er0.025F2.045 on plant (Solanum lycopersicum) photochemistry. The composition, structure and size of nanoparticles were tested using X-ray pattern diffraction, scanning electron microscopy, and dynamic light scattering. Nanoparticles are capable of converting infrared radiation into red and green photons. Glasses coated with upconversion luminophores increase the intensity of photosynthetically active radiation and absorb the ultraviolet and far-red radiation. The chlorophyll a fluorescence method showed that plants growing under photoconversion and those growing under common film demonstrate different ability to utilize excitation energy via photosynthesis. It was shown that under ultraviolet and high light conditions, the efficiency of the photochemical reactions, the non-photochemical fluorescence quenching, and the electron transport remained relatively stable in plants growing under photoconversion film in contrast to plants growing under common film. Thus, cultivation of Solanum lycopersicum under photoconversion glasses led to the acceleration in plant growth due to greater efficiency of plant photochemistry under stress conditions.