6182
Research Article
Vol. 54, No. 20 / July 10 2015 / Applied Optics
0.95 W high-repetition-rate, picosecond 335 nm laser based on a frequency quadrupled, diode-pumped Nd:YVO4 MOPA system W. TU,1,2 L. Q. SHANG,1 S. B. DAI,1,2 N. ZONG,*,1 Z. M. WANG,1 F. F. ZHANG,1 Y. CHEN,1,2 K. LIU,1 S. J. ZHANG,1 F. YANG,1 Q. J. PENG,1 D. F. CUI,1 AND Z. Y. XU1 1
Research Center for Laser Physics and Technology, Key Lab of Functional Crystal and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China 2 University of Chinese Academy of Sciences, Beijing 100190, China *Corresponding author:
[email protected] Received 11 May 2015; revised 10 June 2015; accepted 16 June 2015; posted 17 June 2015 (Doc. ID 240792); published 3 July 2015
An efficient all-solid-state picosecond (ps) ultraviolet (UV) laser at 335 nm was demonstrated based on frequency quadrupling of a mode-locked 1342 nm MOPA system. An output power of 0.95 W was obtained under a fundamental wave power of 16.38 W, corresponding to a conversion efficiency of 5.8% from infrared to UV. The repetition rate and pulse duration were 77 MHz and 20.2 ps, respectively. The beam quality factor M 2 was measured to be 1.56. This is, to the best of our knowledge, the highest output power at 335 nm. © 2015 Optical Society of America OCIS codes: (140.7090) Ultrafast lasers; (140.3610) Lasers, ultraviolet; (140.4050) Mode-locked lasers; (140.3580) Lasers, solidstate; (140.3480) Lasers, diode-pumped. http://dx.doi.org/10.1364/AO.54.006182
1. INTRODUCTION Compact, efficient laser sources emitting in the ultraviolet (UV) spectral band have wide application in optical data storage, UV spectroscopy, high-definition color printing, and so on [1–9]. Higher photon energy due to shorter wavelengths makes precise machining possible. Besides, based on second-harmonic generation (SHG), vacuum ultraviolet lasers with wavelengths below 170 nm can be obtained, which could equip angleresolved photoelectron spectroscopy (ARPES) to observe a broader region of the momentum space of cuprate superconductors as well as reveal the mechanisms of high-temperature superconductivity. UV sources, no matter continuous wave or pulsed operation, are important to many technological breakthroughs and applications. At present, the available coherent sources in this wavelength region are mostly gas lasers such as the 337 nm nitrogen (N 2 ) laser and the 325 nm helium–cadmium (He–Cd) laser. However, the application of the N 2 laser is seriously limited for the inherently low repetition rate (
