Yisheng Huang

Growth and structure of Nd3+-doped Li3Ba2Y3(WO4)8 crystal with a disorder structure

An Nd3+-doped Li3Ba2Y3(WO4)8 crystal with dimensions up to 32 × 20 × 14 mm3 has been grown by the TSSG method. The Li3Ba2Y3(WO4)8 crystal crystallizes in the monoclinic system with the space group C2/c. The unit cell parameters are a = 5.181(2) A, b = 12.677(7) A, c = 19.161(10) A, β = 92.237(13)° and Z = 2. The Li3Ba2Y3(WO4)8 crystal has a high structure disorder. The spectral properties of Nd3+-doped Li3Ba2Y3(WO4)8 crystal exhibited broad absorption and emission bands, which are caused by the disordered structure of the Li3Ba2Y3(WO4)8 crystal. Therefore, it may be regarded as a laser host material for diode laser pumping.

Structure and spectral properties of Nd3+-doped KBaGd(MoO4)3 crystal with a disorder structure

In order to obtain new, more efficient laser materials for diode laser-pumped lasers, the laser host materials with broad absorption bands are very important. This paper reports the structure and spectral properties of Nd3+ : KBaGd(MoO4)3 crystal. KBaGd(MoO4)3 crystallizes in the monoclinic system with space groupC2/c. The structure analysis shows that KBaGd(MoO4)3 crystal has a disordered structure. The investigation of the spectral properties of Nd3+ : KBaGd(MoO4)3 crystals shows that it exhibits broad absorption and emission bands, which are caused by the disordered structure of the KBaGd(MoO4)3 crystal. The broad absorption band is very suitable for diode laser pumping. To sum up the spectral properties of Nd3+ : KBaGd(MoO4)3 crystal, it may be regarded as a potential solid-state laser material for diode laser pumping.

Growth and spectral characteristics of a new promising stoichiometric laser crystal: Ca9Yb(VO4)7

Abstract A Ca 9 Yb(VO 4 ) 7 crystal with dimensions of Φ23 mm×35 mm was grown successfully by Czochralski method. Its thermal conductivity was 1.06 W/(m·K) at room temperature. The absorption cross-sections at 980 nm were 1.80×10 −20 cm 2 and 1.28×10 −20 cm 2 for π-and σ-polarizations, respectively, with a full-width at half-maximum of 34 nm. The crystal had a broad emission at around 1025 nm with a full-width at half-maximum of 67 nm for π-polarization and 70 nm for σ-polarization. The emission cross-sections of the crystal were calculated by using reciprocity method and Fuchtbauer-Ladenburg formula. The emission cross-sections at 1025 nm were 3.57×10 −20 cm −2 and 1.91×10 −20 cm −2 for π- and σ-polarization, respectively. The fluorescence lifetime was 332 μs. The results indicated that the crystal is a promising femtosecond and tunable laser material.

Growth, structure, spectral and laser properties of Yb3+:LaMgB5O10 – a new laser material

A bulk crystal of Yb3+:LaMgB5O10 was grown successfully by the top seeded solution growth method for the first time to our knowledge. The detailed crystal structure data was given, revealing that the Yb3+:LaMgB5O10 crystal belongs to the monoclinic system with the space group P21/n, and its unit cell parameters are: a = 8.8002 A, b = 7.6136 A, c = 9.4900 A, β = 92.46°, V = 635.3 A3 and Z = 4. Investigation of its polarized spectral properties shows that the Yb3+:LaMgB5O10 crystal has broad, strong absorption and emission cross-sections. A continuous wave laser output of 2.76 W with a slope efficiency of 64.5% was obtained; the laser simultaneously oscillated at 1053 and 1057 nm at a pump power of 7.7 W. The results show that the Yb3+:LaMgB5O10 crystal is a promising laser crystal.

Growth, mechanical, thermal and spectral properties of Cr3+:MgMoO4 crystal.

This paper reports the growth, mechanical, thermal and spectral properties of Cr3+∶MgMoO4 crystals. The Cr3+∶MgMoO4 crystals with dimensions up to 30 mm×18 mm×14 mm were obtained by TSSG method. The absorption cross-sections of 4A2→4T1 and 4A2→4T2 transitions are 12.94×10−20 cm2 at 493 nm and 7.89×10−20 cm2 at 705 nm for E//Ng, respectively. The Cr3+∶MgMoO4 crystal shows broad band emission extending from 750 nm to 1300 nm with peak at about 705 nm. The emission cross-section with FWHM of 188 nm is 119.88×10−20 cm2 at 963 nm for E//Ng. The investigated results showed that the Cr3+∶MgMoO4 crystal may be regarded as a potential tunable laser gain medium.

Growth, Structure and Spectroscopic Characterization of Nd3+-Doped KBaGd(WO4)3 Crystal with a Disordered Structure

The undoped and the Nd3+:KBaGd(WO4)3 crystals were grown by the top seeded solution growth (TSSG) method from a flux of K2W2O7. The structure of the pure crystal was determined by the single-crystal X-ray diffraction method. It crystallizes in the monoclinic symmetry with space group C2/c. In the structure, K+ and Ba2+ ions share the same 8f site with occupancy of 0.464 and 0.536, respectively. The investigation of spectral properties of Nd3+:KBaGd(WO4)3 crystal indicates that it exhibits broad absorption and emission bands, which are attributed to locally disordered environments around the Nd3+ centers. The broad absorption band is suitable for diode laser pumping.

Influence of RNAi knockdown for E‐complex genes on the silkworm proleg development

Larvae of many holometabolous insects possess abdominal appendages called prolegs. Lepidoptera larvae have prolegs in the segments A3-A6. Functions of Lepidoptera hox genes on these abdominal appendages development is still a controversial issue. In this article, we report the use of double strand RNA (dsRNA)-mediated interference (RNAi) to dissect the function of some hox genes, specifically E-complex genes Ubx, abd-A, and Abd-B, in the ventral appendage development of the Lepidoptera silkworm, Bombyx mori. We found that Ubx RNAi caused leg identity in A1 segment, abd-A RNAi caused severe defect of abdominal prolegs and Abd-B RNAi allowed proleg identity in more posterior abdominal segments. These results confirm that Lepidoptera hox genes Ubx and Abd-B have evolved the repressing function to ventral appendage development, which is similar to those of Drosophila. However, Lepidoptera abd-A might have been modified distinctively during evolution, and has important roles in directing the development of prolegs.

Efficient orthogonally polarized dual-wavelength Nd:LaMgB₅O₁₀ laser.

We reported an efficient, continuous-wave, diode-pumped, orthogonally polarized dual-wavelength laser working at 1051.8 and 1081.4 nm in a new neodymium-doped borate crystal, Nd:LaMgB5O10, which was grown by the top-seeded solution growth method. A maximum output power of 5.1 W was obtained with an absorbed pump power of 14.8 W, corresponding to an optical-to-optical conversion efficiency of 34.5% and a slope efficiency of 42.5%. By slightly tilting the laser cavity output mirror, the balanced dual-wavelength emissions were obtained with the total output power as high as 4.2 W. This new efficient dual-wavelength laser may be a promising light source for terahertz generation with a rarely large frequency difference of 7.8 THz through difference frequency generation.

Growth and Spectral Assessment of Yb3+-Doped KBaGd(MoO4)3 Crystal: A Candidate for Ultrashort Pulse and Tunable Lasers

In order to explore new more powerful ultrashort pulse laser and tunable laser for diode-pumping, this paper reports the growth and spectral assessment of Yb3+-doped KBaGd(MoO4)3 crystal. An Yb3+:KBaGd(MoO4)3 crystal with dimensions of 50×40×9 mm3 was grown by the TSSG method from the K2Mo2O7 flux. The investigated spectral properties indicated that Yb3+:KBaGd(MoO4)3 crystal exhibits broad absorption and emission bands, except the large emission and gain cross-sections. This feature of the broad absorption and emission bands is not only suitable for the diode pumping, but also for the production of ultrashort pulses and tunability. Therefore, Yb3+:KBaGd(MoO4)3 crystal can be regarded as a candidate for the ultrashort pulse and tunable lasers.

Growth, structure and spectral properties of Cr3+-doped LiMgAl(MoO4)3 crystals with a disordered structure

In order to obtain new, more efficient tunable laser materials for diode laser-pumping, a laser host material with broad absorption and emission bands is very important. This paper reports on the growth, structure and spectral properties of Cr3+:LiMgAl(MoO4)3 crystals. The Cr3+:LiMgAl(MoO4)3 crystals were grown using the top-seeded solution growth (TSSG) method from a flux of Li2Mo3O10. The LiMgAl(MoO4)3 crystals crystallize in a triclinic symmetry with the space group P and have a highly disordered structure. The investigated spectral properties indicated that the Cr3+-doped LiMgAl(MoO4)3 crystals exhibited broad absorption and emission bands which are attributed to locally disordered environments around the Cr3+ centers. The spectral properties suggested that Cr3+-doped LiMgAl(MoO4)3 crystals are a potential candidate for a tunable laser crystal material.