Shufang He

Realizing intracavity frequency doubling and Q switching by KTP

The electro-optic characteristics of the KTP crystal are analyzed in detail and Q-switched operation of a diode-laser- pumped Nd:YVO4 laser is reported using an intracavity KTP crystal. The KTP crystal was used as both an electro-optic Q- switcher and a frequency-doubling crystal in type II phase matching for generating pulsed green beams. Compared with the conventional frequency-doubling and Q-switching configuration where a Q-switcher and a frequency-doubling crystal was needed, low loss and high efficiency characteristics were realized by only using KTP crystal in our experimental setup. With the new type of KTP crystal doped particular element, the great green pulsed output was obtained continuously for a long time with no sign of electrochromic damage. In this paper, we demonstrated a relatively new and compact intracavity frequency-doubled and Q-switched Nd:YVO4 laser. The short- cavity laser was longitudinally pumped with a diode laser.

Miniature green lasers for optical recording and storage

Here we report LD pumped solidified miniature Nd:YAG laser and Nd:YVO4 laser with KTP crystal as intracavity frequency doubling material. Using 1W LD 70 mW and 80 mW of the green laser output in TEMoo mode have been measured for Nd:YAG laser and Nd:YVO4 laser, respectively. The output stability is better than +/- 3 percent and the beam quality coefficient M2 is smaller than 1.2. The laser is small is size and very suitable for optical recording and storage.

New type of diode-pumped cavity-dumping laser

By combining the techniques of AO (acousto-optic) Q-switching and EO (electro-optic) cavity-dumping, a new type of diode-pumped nanosecond pulsed laser was proposed for the first time. The Q- switched pulses at 1.06micrometers with a peak power of 5.02kW and a pulse width 3.1ns pumped a 1W laser diode on the Nd:YVO4 microchip at the 1kHz repetition rate were obtained. The temporal characteristics of the pulses were analyzed numerically. The experiment results are shown to be in good agreement with theoretical predictions.

LD-pumped high-power laser system

A QCW 100 W LD array side pumped high power laser has been developed. The 1.06 micrometer laser pulse energy of 2 mJ, with the pulse width 20 ns and repetition frequency 70 Hz to approximately 5 KHz is obtained. Using the non-cylinder lens focus system developed by our group, the efficient conversion of pump energy into 1.06 micrometer TEM00 mode is achieved with 17% optical-optical efficiency. The effect of vibrating output coupler in the laser resonator strengths the output power has been found for the first time.

LD-pumped red lasers and its application in Cr:LiSAF laser

We report here the Nd:YAP-KTP red laser pumped by LD for pumping Cr:LiSAF tunable laser. Using a CW 802 nm LD of 3 W, 670 nm CW red laser of 95 mW has been measured. The red laser is used to pump Cr:LiSAF laser, and over 4 mW CW laser from the Cr:LiSAF laser has been measured. They are to our knowledge the first Nd:YAP-KTP red laser pumped by LD and the first Cr:LiSAF laser pumped by Nd:YAP-KTP red laser.

LD pumped Q-switched self-frequency-doubling laser

We report here LD pumped Q-Switched LNYAB Self-frequency-doubling Laser. Under 570mW of O.8O2.tm pumping power, the series pulses of O.53j.im green laser with 4.2ns of pulse width and 750W of peak power have been measured . The laser reliably operates when Q—switching rate ranges from CW to 100kHz. The highest peak power was obtained at repetition rate of 10kHz. To our knowledge, it is the first LD pumped acoustooptic Q-switched LNYAB green laser in the world and should be a desirable and reliable pulsed green laser source in the future. KEY WORDS: Self-frequency-doubling Laser, LD Pumped, LNYAB, Q-Switched

Miniature 1.06-um lasers for pumping EDFA

Here we report the LD pumped miniature 1.06 micrometers Nd:YAG solid lasers. Pumped by the LD of 1 W power, 420 mw of 1.06 micrometers CW laser has been obtained. The output stability is better than +/- 3%, and the divergence angle is smaller than 4 mrad. The volume of the device is very small and it is suitable to be applied in the optical fiber communication systems and optical fiber sensing system.