C. L. Li

Diode-Pumped Nd:YVO4-Nd:YLF Blue Laser at 488 nm by Intracavity Sum-Frequency-Mixing

We report a laser architecture to obtain continuous-wave blue radiation at 488 nm. A 808 nm diodepumped the Nd:YVO4 crystal emitting at 914 nm. A part of the pump power was then absorbed by the Nd:YVO4 crystal. The remaining was used to pump the Nd:YLF crystal emitting at 1047 nm. Intracavity sum-frequency mixing at 914 and 1047 nm was then realized in a LBO crystal to reach the blue radiation. We obtained a continuous-wave output power of 514 mW at 488 nm with a pump laser diode emitting 19.6 W at 808 nm.

Diode-pumped continuous-wave Nd:YLF laser at 1313 nm

We present an efficiency Nd:LiYF4 (Nd:YLF) laser operating at 1313 nm pumped directly into the emitting level 4F3/2. At the incident pump power of 10.3 W, as high as 3.1 W of continuous-wave output power at 1313 nm is achieved. The slope efficiency with respect to the incident pump power was 36.1%. To the best of our knowledge, this is the first demonstration of such a laser system. Comparative results obtained for the pump with diode laser at 806 nm, into the highly absorbing 4F5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.

Diode-pumped Nd:YCOB self-frequency-doubling green laser at 530 nm

We report a continuous-wave (CW) self-frequency-doubling blue laser at 468 nm by a diodepumped Nd3+:YCa4O(BO3)3 (Nd:YCOB) laser. With 14.3 W of diode pump power, a maximum output power of 211 mW in the blue spectral range at 468 nm has been achieved. The beam quality M2 values were equal to 1.16 and 1.23 in X and Y directions, respectively. The output power stability over 30 min is better than 5%. To the best of our knowledge, this is the highest power laser at 468 nm generated by self-frequency doubling of a diode pumped Nd:YCOB laser.

Continuous-wave dual-wavelength operation of a diode-end-pumped Nd:GGG laser

A dual-wavelength continuous-wave (CW) diode-pumped Nd:LuVO4 laser that generates simultaneous laser action at the wavelengths 1066 and 1343 nm is demonstrated. A total dual-wavelength output power of 2.58 W was achieved at the incident pump power of 18.2 W. Furthermore, intracavity sum-frequency mixing at 1066 and 1343 nm was then realized in a LBO crystal to reach the yellow range. We obtained a total CW yellow output power of 830 mW at 594 nm.

Long-pulse laser-induced damage in an optical anti-reflective film: II. Experimental research

In order to verify the result of theoretical analysis about long-pulse flat-topped multi-Gaussian laser-induced damage in an optical anti-reflection film with HfO2/SiO2 composite film coating on a BK7 substrate (BK7:HfO2/SiO2), an experimental system was built, which carried out the experiment and analysis, focusing on the pulse-length 1.0 ms, flat-topped laser-induced damage. The result shows that the thermal effect is the main reason for damage under the long-pulse flat-topped laser. Moreover, the stripping and shedding occur because of the heating stress of the film happening at an early stage of the laser irradiation. However, the crack happens at laser irradiation termination. The correctness of the theoretical analysis results is verified.

Diode-pumped Nd:YVO4 laser emitting at 1074 nm based on the 4F3/2-4I11/2 transition

We report a diode-pumped Nd:YVO4 laser emitting at 1074 nm, based on the 4F3/2-4I11/2 transition, generally used for a 1064 nm emission. A power of 323 mW at 1074 nm has been achieved in continuouswave (CW) operation with a fiber-coupled laser diode emitting 18.2 W at 808 nm. Intracavity second-harmonic generation in CW mode has also been demonstrated with a power of 18 mW at 537 nm by using a LiB3O5 (LBO) nonlinear crystal.

Diode-pumped CW Nd:YAG laser at 1116 nm based on the 4F3/2-4I11/2 transition

We describe the output performances of the 1356 nm 4F3/2-4I13/2 transition (generally used for a 1319 nm transition) in Nd:YAG under in-band pumping with diode laser at the 809 nm wavelength. An end-pumped Nd:YAG crystal yielded 1.02 W of continuous-wave (CW) output power for 18.2 W of incident pump power. Moreover, intracavity second-harmonic generation (SHG) has also been achieved with a power of 290 mW at 678 nm by using a LiB3O5 (LBO) nonlinear crystal. The red beam quality factor M2 was less than 1.37. The red power stability was less 3.2% in 4 h.

Efficient intracavity frequency-doubled Nd:YLiF4-LiB3O6 red laser emission under diode pumping into the emitting level

We report for the first time (to our knowledge) an efficient compact red laser at 660.5 nm generation by intracavity frequency doubling of a continuous wave laser operation of a diode direct pumped Nd:YLiF4 (Nd:YLF) laser on the 4F3/2 → 4I13/2 transition at 1321 nm. A LiB3O6 (LBO) crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an absorbed pump power of 16.2 W, as high as 1.5 W of continuous wave output power at 660.5 nm is achieved with 10-mm-long LBO. The optical-to-optical conversion efficiency is up to 9.3%. Comparative results obtained for the pump with diode laser at 806 nm, into the highly-absorbing 4F5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.

Progress in cancer diagnosis and treatment based on gold nanorods

In this paper, the progress in cancer diagnosis and treatment were reviewed which is based on gold nanorods (Au-NRs). Synthesis and properties of Au-NRs were described, more specifically on typical methods of surface modification, surface active agent selection, as well as biological image and cancer treatment which are based on Au-NRs. Also current difficulty and future development were discussed.

Raman spectrum calculation and analysis of glyphosate

Glyphosate is an efficient, low toxicity, non-selective post-emergence herbicide. In this work, Glyphosate molecular structure was optimized by Hartree-Fock(HF) approximation method. Glyphosate molecular Raman and infrared spectra was calculated based on HF/6-31G sets and DFT/6-31G sets, then two theoretical Raman spectra were carefully compared with others experimental spectra, good agreements were obtained between the theoretical and experimental results. Glyphosate structure parameters were also given in the paper including bond lengths and bond angles etc. Vibrational modes were assigned to all bands between 850 cm-1 and 1050 cm-1 range. This work will promote the research of glyphosate molecule in pesticide residues field.