D.R. Yuan

Synthesis, structure and properties of a new nonlinear optical material: zinc cadmium tetrathiocyanate

In this communication, a new nonlinear optical crystal of coordination complex, zinc cadmium tetrathiocyanate (ZnCd(SCN)4), is reported. It was successfully synthesized through several reactions in water. For the crystal structure, optical and thermal characterization were determined by elemental analysis, X-ray diffraction, infrared spectroscopy, differential scanning calorimeter, thermogravimetric analysis, and transmission spectrum. It belongs to the tetragonal system, space group I4, with a = 11.135(2), c = 4.3760(10) A, and z = 2. It exhibits powder SHG efficiencies superior to that of cadmium mercury thiocyanate (CMTC) and over 10 times that of urea, and the UV transparency cutoff is 290 nm, which is shifted to violet band 90 nm, compared with that of CMTC.

Structure and properties of a complex crystal for laser diode frequency doubling: Cadmium mercury thiocyanate

The crystal structure of cadmium mercury thiocyanate [CdHg(SCN)4] is determined by means of a four circle diffractometer. The structural features and properties of the crystal are described. Blue-violet light output by frequency doubling of a 809 nm GaAlAs laser diode using a cadmium mercury thiocyanate crystal device that is 3 mm thick at the phase matching angle: θ=47.7°, φ=0°, is realized at room temperature with input power lower than 200 mW. A 404.5 nm light output power of 1.8 mW is also measured for a 576 mW input power of the GaAlAs laser diode.

Investigation of Bimetallic Thiocyanates belonging to ABTC Structure Type: ZnCd(SCN)4 and AHg(SCN)4 (A = Zn, Cd, Mn ) as Nonlinear Optical Crystal Materials

Bimetallic thiocyanate complexes crystal materials belonging to ABTC structure type: ZnCd(SCN) 4 and AHg(SCN) 4 (A = Zn, Cd, Mn) which are potentially useful in second harmonic generation (SHG) have been prepared. Their structural, optical and physicochemical properties are characterized by infrared spectroscopy, X-ray powder diffraction, vis/UV/NIR spectroscopy, SHG measurements and thermal analysis. The states of crystal growth solutions are discussed in this article. The crystals belong to tetragonal system with the space group I4 and exhibit SHG efficiencies over one order of magnitude higher than that of urea. Their transparency cutoffs lie in the UV region, and they possess good physicochemical stabilities.

The quality and performance of the organometallic complex nonlinear optical material tri-allylthiourea cadmium chloride (ATCC)

Abstract Large (30x30x25 mm) crystals of the organometallic, nonlinear optical material ATCC have been prepared by growth from solution in optically and structurally highly perfect state. Type I phase-matched SHG was observed for 1.064 μm radiation incident at 36.8°. The whole nonlinear coefficient was carried out by Maker-fringe (MF) method.

Crystal growth and characterization of the organometallic nonlinear optical crystal : manganese mercury thiocyanate (MMTC)

Manganese mercury thiocyanate (MMTC) has been discovered to be a novel organometallic nonlinear optical crystal. In this article, preparation and crystal growth of MMTC have been investigated. The crystal grown is characterized by infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and transmission spectrum. The cutoff wavelength is 373 nm, which is nearly the same as that of cadmium mercury thiocyanate (CMTC). The thermoanalysis shows that it possesses better physicochemical stability than that of CMTC.

Growth of cadmium mercury thiocyanate single crystal for laser diode frequency doubling

Abstract Cadmium mercury thiocyanate (CdHg(SCN) 4 , CMTC) crystal is one of the most efficient nonlinear optical crystals among complex crystals. Two different solvent mixtures of water–NaCl and water–KCl suitable for growing CMTC crystal are reported for the first time. A typical single crystal of CMTC with size 18×18×25xa0mm 3 was grown from a water–NaCl mixture solvent by using temperature-lowering method.

The effect of Co2+ and Co3+ on photoluminescence characteristics of ZnS nanocrystallines

Abstract Free-standing powder of doped ZnS nanoparticles has been synthesized by using a chemical co-precipitation of Zn 2+ , Co 2+ , Co 3+ with sulfur ions in aqueous solution. X-ray diffraction analysis shows that the diameter of the particles is ∼2.6±0.2xa0nm. Unique luminescent properties have been observed from ZnS nanoparticles doped with Co 2+ and Co 3+ . The effect of Co 3+ on emission spectra of doped samples is remarkably different from that of Co 2+ . Very strong and stable visible-light emission have been observed from ZnS nanoparticles doped with Co 2+ . However, the fluorescence intensity of Co 3+ -doped ZnS nanoparticles is much weaker than that of ZnS nanoparticles. Nanoparticles can be doped with cobalt during the synthesis without altering the X-ray diffraction pattern and emission wavelength. However, doping makes the fluorescence intensity vary. The fluorescence intensity of doped sample is about five times of that of pure ZnS nanocrystallines when the doped mole ratio of Co 2+ is 0.5%. The fluorescence efficiencies of samples decreases as doped mole ratio of Co 2+ and Co 3+ increases. When Co 3+ is doped in ZnS nanoparticles, the fluorescence efficiencies of doped ZnS nanoparticles almost died away. Therefore, Co 3+ leads to fluorescence decay of ZnS nanocrystallites.

Novel organic molecular second harmonic generation crystal : 3-methoxy-4-hydroxy-benzaldehyde

In considering the trade‐off between second‐order nonlinearity and transparency, a new organic molecular crystal 3‐methoxy‐4‐hydroxy‐benzaldehyde (MHBA) has been grown from solution by the temperature lowering method for the first time. MHBA belongs to the monoclinic system, and its space group is P21. The unit cell dimensions are: a=14.057, b=7.875, c=15.037 A with β=115.45°. The powder second harmonic generation of MHBA is 30 times higher than that of urea and the cutoff wavelength is 370 nm.

Preparation and Characterization of Nonlinear Optical Crystal Materials: Cadmium Mercury Thiocyanate and its Lewis Base Adducts

Cadmium mercury thiocyanate (CdHg(SCN) 4 , CMTC) and its two lewis base adducts: cadmium mercury thiocyanate dimethyl-sulphoxide (CdHg(SCN) 4 (H 6 C 2 OS) 2 , CMTD) and cadmium mercury thiocyanate glycol monomethyl ether (CdHg(SCN) 4 (C 3 H 8 O 2 ), CMTG) have been discovered as nonlinear optical (NLO) crystal materials. Their structural, optical and physicochemical properties were characterized by X-ray powder diffraction (XRPD), infrared spectroscopy, vis/UV/NIR spectra and thermal analysis. It is discovered that their transparency cutoffs lie in the UV region and CMTD crystals possess the shortest cutoff wavelength among the three crystal materials.

Physicochemical behavior of nonlinear optical crystal CdHg(SCN)4

Abstract The preparation and purification of cadmium mercury thiocyanate, CdHg(SCN)4 (CMTC) are described. The identity of the synthesized compound was characterized by Raman, infrared and X-ray powder diffraction spectra. The thermal stability and thermal decomposition of CMTC crystals were investigated by means of thermogravimetric analysis and differential scanning calorimetry. The impurities in the growth solutions and their effects are discussed.