Junhua Lu

Second-harmonic generation from a KBe(2) BO(3)F(2) crystal in the deep ultraviolet.

By use of KBe(2)BO(3)F(2) (KBBF) crystal with a size of 10 mmx10 mm x1.2 mm and a special prism-coupling technique (PCT), fourth-harmonic generation of Ti:sapphire laser systems from 200 to 179.4 nm has been achieved. Moreover, with a Ti:sapphire laser with a 50-fs pulse duration and a 1-kHz repetition rate, conversion efficiency as high as 13% from 400 to 200 nm without any surface-loss correction has also been obtained. The data show that with the PCT a KBBF crystal can produce deep-UV coherent light with measurable power output.

Efficient second harmonic generation in a new nonlinear La2CaB10O19 crystal

Abstract In this report, the second harmonic generation in a newly developed nonlinear crystal La 2 CaB 10 O 19 was investigated. A second harmonic conversion efficiency of 25% was obtained. Effective nonlinear coefficient of 1.05 pm/V at the wavelength of 1064 nm was determined by comparing with β-BaB 2 O 4 and CsB 3 O 5 , which is larger than that of KH 2 PO 4 and LiB 3 O 5 .

High-efficiency fourth-harmonic generation of KBBF crystal

A prism-coupled technique (PCT) was introduced in the SHG experiment of KBe2BO3F2 (KBBF) crystal. 266-nm ultraviolet energy of 0.28 mJ was obtained by using this method in a KBBF crystal at the input energy of 2.6 mJ, corresponding to a conversion efficiency of 10.8%.

Second harmonic generation from KBBF crystal in the deep ultraviolet

By using a KBe/sub 2/BO/sub 3/F/sub 2/ (KBBF) crystal with a size of 10 /spl times/ 10 /spl times/ 1.2 mm/sup 3/ and a special prism coupling technique (PCT), the fourth-harmonic generation of Ti:sapphire laser systems from 200 nm to 179.4-nm has been achieved for the first time. Moreover, by a Ti:sapphire laser with a 50-fs pulse duration and a 1-kHz repetition rate. A conversion efficiency as high as 13% from 400 nm to 200 nm has also been obtained without any surface loss correction.

Optical characterization of a new lanthanum and calcium borate La/sub 2/CaB/sub 10/O/sub 19/

Summary form only given. Since powerful, tunable ultraviolet laser sources rely on the frequency-doubling of lasers in the visible range, the search for new nonlinear optical (NLO) materials for ultraviolet and blue-green spectroscopic applications has received increasing attention. In the past few years a new NLO crystal YCa/sub 4/O(BO/sub 3/)/sub 3/ (YCOB) has attracted considerable interest because it exhibits a relatively large second harmonic generation (SHG) effect, and the single crystal is easily grown. Recently a new lanthanum and calcium borate with the composition La/sub 2/CaB/sub 10/O/sub 19/ was identified by our group. This compound possesses the significant feature comparable with that of YCOB. In this paper, we report the linear optical and nonlinear optical properties of La/sub 2/CaB/sub 10/O/sub 19/ crystal (LCB).

Generation of vacuum-ultraviolet light by an optical contact, prism-coupled KBBF crystal

We generated the second harmonic of a frequency-tripled Nd:YVO/sub 4/ laser with an quasi-CW, 2.5-mW output and also the shortest-wavelength second harmonic at 172.5 nm and sum-frequency mixing at 163.3 nm by an optical contact, prism-coupled KBe/sub 2/BO/sub 3/F/sub 2/ (KBBF) crystal.

Growth and second harmonic generation characteristics of La/sub 2/CaB/sub 10/O/sub 19/ crystal

Single crystals of La/sub 2/CaB/sub 10/O/sub 19/ (LCB) were grown by the pulling method. The second harmonic generation conversion efficiency of a picosecond Nd:YAG laser is 25% for a 3mm long LCB crystal and 6GW/cm/sup 2/ pump intensity.