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Optical transmission range and phase matching (PM) conditions for second harmonic generation (SHG) of Er3+:YSGG and CO2 laser in indium doped GaSe:In(0.1, 1.23, 2.32 mass%) are studied in comparison with these in pure and sulfur doped GaSe:S(0.09, 0.5, 2.2, 3 mass%) crystals. No changes in transparency curve are found in GaSe crystals up to 2.32 mass% indium content, but as small change as 0.18 degrees in PM angle for 2.79 microm Er3+:YSGG laser SHG and approximately 0.06 degrees for 9.58 microm CO2 laser emission line SHG are detected. PM properties of the crystals are evaluated as a function of temperature over the range from -165 to 230 degrees C. The value of dtheta/dT, the change in PM angle with variation of temperature, is found to be very small for GaSe:In crystals. While for SHG of Er3+:YSGG laser, dtheta/dT =22"/1 degrees C only, it is as small as -4.9"/1 degrees C for that of CO2 laser radiation. Linear variation of PM angle with temperature increasing is an indicator of absence of crystals structure transformation within temperature range from -165 to 230 degrees C. Thus, application of GaSe:In solid solutions in high average power nonlinear optical systems seems to be prospective.

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This study helps to elucidate the mechanism underlying the association between parental marital conflict and Internet addiction.

In this letter, we propose a novel multiwavelength fiber laser based on fiber loop mirror formed by a highbirefringence fiber, a polarisation controller, and a 3 dB directional coupler. By setting the polarisation controller as half-waveplate, the fiber loop mirror acts as a polarisation-independent wavelength filter; Erbium-doped fiber (EDF) cooling by liquid nitrogen acts as gain medium. The wavelength spacing between the adjacent modes of the laser can be varied accurately by adjusting the length of the High-Birefringence (HiBi) fiber.

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A transparent vanadium oxide film has been one of the most studied electrochromic (EC) and Thermochromic (TC) materials. Vanadium oxide films were deposited at different substrate temperatures up to 400°C and different ratios of the oxygen partial pressure (P O2). SEM, AFM and X-ray diffraction's results show detail structure data of the films. IR mode assignments of the films measured by IR reflection-absorbance in NGIA (near grazing incidence angle) are given. It is found that the film has V 2 O 5 and VO 2 combined structures. The films exhibit clear changes in transmittance when the environment temperature (T e) is varied, especially in the 3600-4000 cm − 1 range. Applying a T e that is higher than a critical temperature (T c) to the samples, the as-RT (room temperature) deposited film with 9% P O2 has a transmittance variation of 30%, but the films that were deposited on a heated substrate of 400°C have little variation. There is tendency of bigger variation in transmittance for the sample deposited at a larger P O2 , when it is applied by 200°C T e .

Chiral imidodiphosphoric acids were employed as efficient catalysts in the enantioselective addition reaction of pyrrole and indoles to 3-vinylindoles. A series of optically active 1,1,1-triarylethmanes bearing quaternary stereocenters were synthesized in excellent yields (up to 99% yield) and enantioselectivities (up to 98% ee). Gram-scale reactions of 1i and 2a as well as 1o and 5a demonstrated the synthetic utility of this methodology. Control experiments showed that the formation of a double H-bond between the catalyst and substrates is necessary for an excellent outcome.