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oe1(光电查) - 科学论文

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  • Laser-diode dual-end-pumped electro-optic Q-switched slab Tm:YAP laser

    摘要： A high-repetition-rate and double-end pumped electro-optic Q-switched Tm:YAlO3 (Tm:YAP) laser is reported. The Tm:YAP slab crystal cut by c-axis is used as the laser gain medium, and the RbTiOPO4(RTP) crystal is selected as the electro-optic Q-switched crystal. Choosing volume Bragg gratings (VBG) as the input mirror to narrow the output line width. When the pump power is 79.2 W, at a repetition rate of 10 kHz, maximum average-output-power of 21.96 W is achieved, with the pulse width of 20.64 ns and output energy of 2.20 mJ. The output peak power is 107.3 kW and the slope efficiency is 29.2%. The center wavelength is 1937.87 nm and the line width is 0.73 nm. The beam quality in the x direction is 1.48, and in the y direction is 1.50.

    关键词： Electro-optic Q-switch,High repetition rate,Tm:YAP laser,RTP

    更新于2025-09-23 15:19:57

  • Nd:YAP laser in the treatment of dentinal hypersensitivity: An ex vivo study.

    摘要： Purpose: The aims of this ex vivo study were to evaluate the effectiveness of the Nd:YAP laser in the treatment of dentin hypersensitivity, to compare the temperature rise during laser irradiation at three different dentine thicknesses, and to analyse the composition of the dentine-lased surface. Methods: A total of 33 teeth were used in this study. For scanning electron microscopy (SEM) observation, 24 teeth were transversely sectioned and divided into 4 groups: group A was irrigated with EDTA; group B was irradiated by Nd:YAP laser with 180 mJ energy/per pulse, 0.9 W average power, and 5 Hz frequency (power density [PD] = 229 W/cm2); group C was irradiated by Nd:YAP laser with 280 mJ energy/pulse, 1.4 W average power, and 5 Hz frequency (PD = 356 W/cm2); and group D was irradiated by Nd:YAP with 360 mJ energy/pulse, 1.8 W average power, and 5 Hz frequency (PD = 458W/cm2). Energy-dispersive spectroscopy (EDS) analysis was performed on the same teeth evaluated for SEM observations. For temperature increase evaluation performed with thermocouples, 9 teeth were transversely sectioned at 3 different thicknesses (3 for each group) of 1, 2, and 3 mm. Results: Statistical analysis showed significant changes in the diameter of the dentinal tubule orifices among all groups; EDS did not show modification of the Ca/P ratio. Temperature increase under irradiation exceeded 5.5°C only in the group D samples. Conclusions: This ex vivo study, based on temperature recording, SEM observation, and EDS analysis, demonstrated that Nd:YAP laser at a PD of 356 W/cm2, corresponding to an average power of 1.4 W, defines the best treatment for dentine hypersensitivity in terms of compromise between efficacy of the treatment and safety of the pulp.

    关键词： dentinal hypersensitivity,energy-dispersive spectroscopy,thermal evaluation.,Nd:YAP laser,scanning electron microscopy

    更新于2025-09-12 10:27:22