Short-wavelength Edge Research Articles (Page 1)

Birefringent crystals are indispensable components in optical functional devices that enable the precise manipulation of light polarization. However, achieving a balance between wide ultraviolet (UV) transparency and significant birefringence poses a formidable challenge due to their inherent inverse correlation. Here, we report a novel rare-earth borate fluoride, K2GdB3O6F2 (KGBOF) that overcomes this intrinsic trade-off via the rational assembly of π-conjugated [B3O6] groups. Expectedly, KGBOF exhibits a large birefringence of 0.12@532 nm, comparable to that of the commercially available α-BaB2O4, exceeding that of most rare-earth borate fluorides. Notably, KGBOF demonstrates a wide band gap of 5.71 eV and a short-wavelength cutoff edge (<200 nm). First-principles calculations and structural analysis attribute the exceptional optical anisotropy to the coplanar alignment of π-conjugated [B3O6] clusters. These results establish KGBOF as a promising short-wave UV birefringent crystal and provide a basis for the exploitation of new birefringent materials in the short-wavelength region.

It has been found that hetero layers of typical β-ZnSe and atypical α-ZnSe modifications can be obtained by the isovalent substitution method. Isovalent impurities are formed which predetermine the formation of dominant radiation with a quantum yield of η = 12–15% in the short wavelength edge region. Low-temperature studies and λ-modulation techniques allowed us to identify the radiation components. This radiation is generated by interband recombination and exciton annihilation. The high temperature stability of the radiation was confirmed over temperature variations including 77, 300, and 480 K.

Attractive depletion interactions are utilized to organize colloidal particles into crystalline arrays with high crystallinity through spontaneous phase separation. However, uncontrolled nucleation frequently leads to the formation of crystalline grains with varied crystal orientations, which hampers the optical performance of photonic crystals. Here, colloidal crystals have been engineered with uniform orientation and high surface coverage by applying centrifugal force during the depletion-induced assembly of polystyrene particles. The centrifugal force encourages the particles to move toward the bottom surface, which fosters heterogeneous nucleation and supports rapid crystal growth, yielding densely-packed and uniformly-arranged crystal grains with high reflectivity. This study has observed that the nucleation and crystal growth behavior is significantly influenced by the salt concentration. Based on the pair potentials, the transition boundary has been quantitatively analyzed between fluid and crystal phases and identified the threshold for homogeneous nucleation. Utilizing the high-reflectivity colloidal crystals, band-edge lasing is achieved by dissolving the water-soluble dye into the aqueous suspensions. Upon optical excitation, a lasing emission characterized is observed by a narrow spectral width at the short-wavelength band edge. Notably, the laser wavelength can be adjusted by altering the salt concentration or particle diameter, offering a versatile approach to tuning the optical properties.

Raman-scattering-assisted noise-like pulse generation in an all-PM NOLM-based mode-locked fiber laser core-pumped by a 978 nm fiber laser

Effect of iodine on physicochemical and optical properties of Ge20Te77-xSe3Ix (x = 0–10) glasses

Synthesis and study of single crystals and optical ceramics based on the AgCl0.25Br0.75 – AgI system

Near infrared voltage sensitive dyes based on chromene electron donors.

In this paper, we study the photoelectric properties of pCdTe-nCdS and pCdTe-nCdSe-based film heterostructures. It is shown that the high value of the electron diffusion length in pCdTe slick (pellicle) is due to the presence of a built-in field in it. When studying the effect of temperature on the spectral characteristics, it was found that with increasing temperature, the maximum photosensitivity of the heterostructure shifts towards longer wavelengths of light. The shift in the photosensitivity maximum is explained by changes in the band gap of cadmium telluride. As shown, the accumulation coefficient increases with raising thickness of the wide-gap layer. It has been established that the short-wavelength edge of the photosensitivity of the pCdTe-nCdS structure begins to increase sharply at a photon energy of hv ≤ 2,3 eV, while the photosensitivity of the pCdTe-nCdSe structure already at a photon energy has a significant value ~ 100 μA/mV.

In this paper, we study the photoelectric properties of pCdTe-nCdS and pCdTe-nCdSe-based film heterostructures. It is shown that the high value of the electron diffusion length in pCdTe slick (pellicle) is due to the presence of a built-in field in it. The shift in the photosensitivity maximum is explained by changes in the band gap of cadmium telluride. As shown, the accumulation coefficient increases with raising thickness of the wide-gap layer. It has been established that the short-wavelength edge of the photosensitivity of the pCdTe-nCdS structure begins to increase sharply at a photon energy of hv ≤ 2,3 eV, while the photosensitivity of the pCdTe-nCdSe structure already at a photon energy has a significant value ∼ 100 μA/mV.

Optical ceramics based on TlCl0.74Br0.26 – AgI system transparent from visible to far IR region

Microscopy with extreme ultraviolet (EUV) radiation holds promise for high-resolution imaging with excellent material contrast, due to the short wavelength and numerous element-specific absorption edges available in this spectral range. At the same time, EUV radiation has significantly larger penetration depths than electrons. It thus enables a nano-scale view into complex three-dimensional structures that are important for material science, semiconductor metrology, and next-generation nano-devices. Here, we present high-resolution and material-specific microscopy at 13.5 nm wavelength. We combine a highly stable, high photon-flux, table-top EUV source with an interferometrically stabilized ptychography setup. By utilizing structured EUV illumination, we overcome the limitations of conventional EUV focusing optics and demonstrate high-resolution microscopy at a half-pitch lateral resolution of 16 nm. Moreover, we propose mixed-state orthogonal probe relaxation ptychography, enabling robust phase-contrast imaging over wide fields of view and long acquisition times. In this way, the complex transmission of an integrated circuit is precisely reconstructed, allowing for the classification of the material composition of mesoscopic semiconductor systems.

Research on a novel chalcohalide glass and its physical optics properties

Structure- and excitation-dependent photoluminescence of As–S:Yb3+ films

In this work, we show that the nonlinear evolution of femtosecond seed pulses with different parameters (temporal and spectral shapes, repetition rate, pulse energy) in an Yb-fiber amplifier leads to gain-managed nonlinear amplification, enabling robust generation of high-peak-power and nearly transform-limited pulses after external compression. We demonstrate a compressed pulse duration of 33 fs with an energy of 80.5 nJ and a peak power of 2.29 MW for a source with a repetition rate of 30 MHz. For a second seed source with a repetition rate of 125 MHz, we obtained a pulse duration of 51 fs with an energy of 22.8 nJ and a peak power of 420 kW. Numerical simulations incorporating rate equations and nonlinear propagation in the amplifier provide evolutions that agree well with the experimental results. The discrepancies in the amplifier’s absorption edge appearing at low repetition rates and higher pump powers are attributed to the temperature dependence of the amplifier’s gain cross-sections. Here, we experimentally verify this attribution and thus underline the importance of accounting for the fiber core temperature for precise modelling of the short-wavelength spectral edge of the output pulses in nonlinear Yb-fiber amplifiers. We also measure, for the first time, the relative intensity noise of an amplifier operating in the gain-managed nonlinear regime. The measurements reveal a significant contribution of the amplification process to the overall output noise of the system.

We have carried out an experimental study of the VUF- edge of the optical host absorption of lithium borate crystals LiB3O5 (LBO) and Li2B4O7 (LTB). The transmission (T=293 K) and absorption (T=80, 293 K) spectra were studied, the short-wavelength edge of the transparency band (cutoff wavelength) and the energy position of the edge fundamental absorption at which the absorption coefficient k=50 cm-1 were determined. The absorption edge temperature shift coefficient -(3-4.7)·10-4 eV/K was determined. The dependence of the absorption edge parameters of oriented LBO normal Y and LBO normal X crystals has been studied. Based on low-temperature reflection spectra (T=10 K, theta=17o, E=4-32 eV) the Kramers-Kronig method was used to calculate the spectra of optical constants: refractive index (n) and absorption index (k), real (ε1) and imaginary (ε2) parts of the complex permittivity, as well as the absorption coefficient μ. The lowest energy peak, due to electronic transitions from the top of the valence band to the states of the bottom of the conduction band, was studied in the ε_2(E) spectrum, the thresholds for interband transitions were determined (Eg at T=10 K): 8.5-8.6 eV(LBO normal Y), 8.6-8.7 eV (LBO normal X) and 8.8-8.9 eV (LTB). The origin of the fundamental absorption edge of lithium borates is discussed. Keywords: Lithium triborate LiB3O5, lithium tetraborate Li2B4O7, host absorption edge, optical properties.

The spectrum of spin waves (SW) of tangentially magnetized films of yttrium iron garnet (YIG) with a surface metastructure in the form of gratings of etched grooves with a period Λ close to the film thickness d (Λ~d) has been experimentally and numerically studied. It has been found that the spectrum of the signal reflected from a microstrip transducer with a width w&gt;&gt;d,Λ located on the YIG film contains absorption lines associated with the excitation of the SW of the surface metastructure. In the case when the magnetic field H and the transducer are oriented along the grooves, the absorption lines of the metastructure are located at frequencies f* near the short-wavelength edge of the spectrum of the surface magnetostatic (Damon-Eshbach) wave fs. It is shown that f* linearly depends on H , which can be used to develop magnetic field sensors. The results of measurements of dependences f* (H) are in qualitative agreement with the results of micromagnetic modeling.

We have carried out an experimental study of the VUV edge of the optical host absorption of lithium borate crystals LiB3O5 (LBO) and Li2B4O7 (LTB). The transmission (T = 293 K) and absorption (T = 80, 293 K) spectra are studied, the short-wavelength boundary of the transparency band (cutoff wavelength) and the energy position of the edge are determined. fundamental absorption at which the absorption coefficient is k = 50 cm-1. The transmission (T = 293 K) and absorption (T = 80, 293 K) spectra were studied, the short-wavelength edge of the transparency band (cutoff wavelength) and the energy position of the edge fundamental absorption at which the absorption coefficient k = 50 cm-1 were determined. The absorption edge temperature shift coefficient −(3–4.7)·10-4 eV/K was determined. The dependence of the absorption edge parameters of oriented LBO ⊥ Y and LBO ⊥ X crystals has been studied. Based on low-temperature reflection spectra (T = 10 K, θ = 17◦, E = 4–32 eV) the Kramers – Kronig method was used to calculate the spectra of optical constants: refractive index (n) and absorption index (k), real (ε1) and imaginary (ε2) parts of the complex permittivity, as well as the absorption coefficient μ. The lowest energy peak, due to electronic transitions from the top of the valence band to the states of the bottom of the conduction band, was studied in the ε2(E) spectrum, the thresholds for interband transitions were determined (Eg at T = 10 K): 8.5–8.6 eV (LBO ⊥ Y), 8.6–8.7 eV (LBO ⊥ X) and 8.8–8.9 eV (LTB). The origin of the fundamental absorption edge of lithium borates is discussed.

We have carried out an experimental study of the VUV edge of the optical host absorption of cesium-lithium borate crystals CsLiB6O10 (CLBO). The transmission (T=293 K) and absorption (T = 80, 293 K) spectra were studied, the short-wavelength edge of the transparency band (cutoff wavelength) and the energy position of the edge fundamental absorption at which the absorption coefficient k=50 cm-1 were determined. The absorption edge temperature shift coefficient -5.5·10-4 eV/K was determined. Based on low-temperature reflection spectra (T=10 K, theta=17o, E=7-30 eV) the Kramers-Kronig method was used to calculate the spectra of optical constants: refractive index (n) and absorption index (k), real (ε1) and imaginary (ε2) parts of the complex permittivity , as well as the absorption coefficient μ. The lowest energy peak, due to electronic transitions from the top of the valence band to the states of the bottom of the conduction band, was studied in the ε2(E) spectrum, the thresholds for interband transitions were determined Eg=7.95 eV. The origin of the fundamental absorption edge of cesium-lithium borate is discussed. Keywords:: Cesium-lithium borate CsLiB6O10 (CLBO), host absorption edge, optical properties.

The spectrum of spin waves (SW) of tangentially magnetized films of yttrium iron garnet (YIG) with a surface metastructure in the form of gratings of etched grooves with a period close to the film thickness d (~ d) has been experimentally and numerically studied. It has been found that the spectrum of the signal reflected from a microstrip transducer with a width w&amp;gt;&amp;gt; d, located on the YIG film contains absorption lines associated with the excitation of the SW of the surface metastructure. In the case when the magnetic field H and the transducer are oriented along the grooves, the absorption lines of the metastructure are located at frequencies f* near the short-wavelength edge of the spectrum of the surface magnetostatic (Damon--Eshbach) wave fs. It is shown that f* linearly depends on H, which can be used to develop magnetic field sensors. The results of measurements of dependences f*(H) are in qualitative agreement with the results of micromagnetic modeling. Keywords: magnetostatic waves, one-dimensional grating, surface structure, sensor of magnetic field.

We have carried out an experimental study of the VUV edge of the optical host absorption of cesium-lithium borate crystals CsLiB6O10 (CLBO). The transmission (T = 293K) and absorption (T = 80, 293 K) spectra are studied, the short-wavelength boundary of the transparency band (cutoff wavelength) and the energy position of the edge are determined. fundamental absorption at which the absorption coefficient is k = 50 cm−1. The transmission (T = 293 K) and absorption (T = 80, 293 K) spectra were studied, the short-wavelength edge of the transparency band (cutoff wavelength) and the energy position of the edge fundamental absorption at which the absorption coefficient k = 50cm−1 were determined. The absorption edge temperature shift coefficient −(3–4.7)·10−4 eV/K was determined. The dependence of the absorption edge parameters of oriented LBO⊥ X and LBO⊥ Y crystals has been studied. Based on low-temperature reflection spectra (T =10K, θ =17◦, E = 4–32 eV ) the Kramers –Kronig method was used to calculate the spectra of optical constants: refractive index (n) and absorption index (k), real (ε1) and imaginary (ε2) parts of the complex permittivity , as well as the absorption coefficient μ. The lowest energy peak, due to electronic transitions from the top of the valence band to the states of the bottom of the conduction band, was studied in the ε2(E) spectrum, the thresholds for interband transitions were determined (Eg at T = 10K): 7.95 eV. The origin of the fundamental absorption edge of cesium-lithium borate is discussed.