Search

A compact high power diode-pumped passively mode-locked Nd:YVO4 laser with high repetition rate is realized. Using an Nd:YVO4 crystal and a semiconductor saturable absorber mirror (SESAM) in the oscillator, the picosecond pulse output with an average power of 1.38 W, a repetition rate of 3.24 GHz, and a pulse duration of 11.4 ps is achieved. After one stage of amplification, the final output power reaches 11.34 W, corresponding to a total optical-to-optical efficiency of about 32%. The root mean square (RMS) value of power fluctuation is demonstrated to be less than 0.6% in 24 hours, showing a superior stability with the compact configuration.

A biodegradable SO3H-functionalized ionic liquid (IL) was prepared and used as the catalyst for a one-pot, three-component condensation synthesis of α-aminophosphonates from aldehydes, amines, and triethylphosphite/diethylphosphite at room temperature under solvent-free conditions or in aqueous media. The products could be simply separated from the reaction mixture and the catalyst could be recycled and reused for several times without noticeably reducing catalytic activity.

A biodegradable acyclic SO3H-functionalized ionic liquid has been used as a novel catalyst for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-ones via one-pot multi-component condensation of β-naphthol, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds, under solvent-free conditions, to afford good to excellent yields ranging from 85 to 93 % within 30–60 min. After the reaction the products could be simply separated from the reaction mixture and the catalyst could be recycled and reused several times without noticeable reduction of catalytic activity.