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On the basis of mini-spectrometers, a reference lamp of the SIRSH type with a known color temperature, and line spectrum sources, an inexpensive hardware complex has been created for measuring the emission parameters of heterodiodes and interference filters. Examples of recording the emission of heterodiodes (full width at half maximum is 17–30 nm) with a maximum of emission in the region of 659 and 764 nm and measurement of an interference filter (FWHM of the bandwidth is 12 nm) with a maximum transmission of 727 nm are given. The emission parameters of the SIRSH standard lamp are introduced into the program for measuring and processing data, due to which it is possible to significantly refine the value of the wavelength of the maximum emission and transmission.

The results of the study of the degradation of thermoluminescent materials Li2B4O7:Be + Mn and Li2B4O7:Zn + Mn under the effect of radiation (pulsed electron beam) and laser radiation are presented. As a result of exposure to high doses of radiation, the structure of the samples under study partially acquires an amorphous character, while the effect of radiation exposure is manifested in the optical properties in the appearance of green luminescence due to manganese centers in the tetrahedral environment. With subsequent irradiation with a laser at a wavelength of 350 nm, luminescence centers decay due to photochemical oxidation of manganese by the reaction of Mn2+ → Mn3+. It is shown that Li2B4O7:Be + Mn has a lower radiation resistance than Li2B4O7:Zn + Mn.

Sub-nanosecond luminescence of Mn2+ in Mn-, Sn/Mn-, and Cu/Mn-doped Li2B4O7 ceramics is observed under laser excitation. Picosecond pulsed laser radiation (350–370 nm) generates the frequency-doubled radiation directly in a single microcrystal selected in a ceramic sample, with this secondary radiation falling within the impurity-induced VUV excitation bands of doped Li2B4O7. These excitation bands are attributed to the creation of an impurity-bound intra-anionic exciton in MeiO4–BO3–MnLi complex centres (Mei = Mn, Sn, or Cu). The exciton, in turn, interacts with a nearby Mn2+ ion due to mixing of the Mn2+ excited states with the excitonic states. Exciton annihilation involves Mn2+ energy levels as transient states and causes a sub-nanosecond radiative transition which is accelerated, being accompanied by rearrangement of the surrounding atoms. Excitation within the lower-energy bands is related to the other part of the complex luminescence centre, this is metal-to-ligand intra-anionic charge transfer, which makes an electron accessible to MnLi, while the hole is transferred only during relaxation of the excited structure. Mn2+ radiative transitions are not forced in the latter case, and slow Mn2+ luminescence decay is observed.

An investigation was made of the influence of the intensity of picosecond (?p ? 23 ps) laser pulses on the kinetics of the photosynthesis of previtamin D3. An increase of the intensity from 1012 to 1014 W m-2 resulted in significant changes in the photosynthesis kinetics: the photoreaction rate fell and so did the efficiency of the cis?trans isomerisation of previtamin D. An analysis showed that two-step absorption made only a small contribution to these effects and that they were mainly associated with the excitation of nonequilibrium conformers of the previtamin molecule.

Picosecond pulses of the fifth harmonic of a YAG : Nd laser were used to study nonlinear absorption in fused quartz and in water at the wavelength of 212.8 nm. The two-photon absorption coefficients of quartz and water were determined. In the approximation of the Gaussian shape for the laser pulses these coefficients were (7.5 ± 0.4)×10-10 and (3.2 ± 0.3)×10-10 cm W-1 for quartz and water, respectively.

Background-free determination of the duration of femtosecond ultraviolet radiation pulses generated in an excimer system was performed for the first time. The method of noncollinear second harmonic generation on reflection from the surface of a nonlinear crystal was used. It was found that amplification of femtosecond pulses in an XeCl excimer amplifier did not exhibit coherent effects.