High Power Laser Science and Engineering, (2018), Vol. 6, e4, 7 pages.
© The Author(s) 2018. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/
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doi:10.1017/hpl.2017.38
Pulsed LD side-pumped MgO: LN electro-optic
cavity-dumped 1123 nm Nd: YAG laser with short pulse
width and high peak power
Yang Bai
1,2,3
, Bing Bai
1,2,3
, Diao Li
1,2,3
, Yanxiao Sun
1,2,3
, Jianlin Li
1,2,3
, Lei Hou
1,2,3
,
Mingxuan Hu
1,2,3
, and Jintao Bai
1,2,3
1
National Key Laboratory of Photoelectric Technology and Functional Materials (Culture Base), Institute of Photonics and Photon-
Technology, Northwest University, Xi’an 710069, China
2
Shaanxi Engineering Technology Research Center for Solid State Lasers and Application, Xi’an 710069, China
3
Provincial Key Laboratory of Photo-electronic Technology, Institute of Photonics and Photon-Technology, Northwest University,
Xi’an 710069, China
(Received 12 November 2017; revised 29 November 2017; accepted 19 December 2017)
Abstract
We report a cavity-dumped 1123 nm laser with narrow pulse width and high peak power by an MgO: LN crystal electro-
optic (EO) modulator. Based on the structural optimization design of a folded biconcave cavity using the 808 nm pulsed
laser diode (LD) side-pumped ceramic Nd: YAG rod, output pulses with maximum pulse energy and peak power up to
39.6 mJ and 9.73 MW were obtained, corresponding to 100 Hz repetition rate and 4.07 ns pulse width. The instabilities
of pulse width and pulse energy were ±1.55% and ±2.06%, respectively. At the highest repetition rate of 1 kHz, the
pulse energy, pulse width, and peak power were 11.3 mJ, 5.05 ns, and 2.24 MW, respectively. The instabilities of pulse
width and pulse energy were ±2.65% and ±3.47%, respectively.
Keywords: cavity-dumped; high peak power; MgO: LN EO; 1123 nm laser; short pulse width
1. Introduction
In recent years, pulsed Nd: YAG lasers with high energy,
narrow pulse width, high peak power and good stability have
been widely used in laser radar, precision machining, op-
tical communications, ranging, medicine, nonlinear optical
frequency conversion, and so on
[1–5]
. The polycrystalline
ceramic Nd: YAG emerges as promising laser gain medium
for high energy, high power all solid-state lasers. It has
similar properties with Nd: YAG crystal in terms of upper-
level lifetime, absorption cross section, extinction ratio and
thermal conductivity. Moreover, ceramic Nd: YAG has ad-
vantages of simple fabrication process, low cost, high doping
concentration and easy batch production
[6–11]
. Generally,
there are three laser radiations in ceramic Nd: YAG, which
emit wavelengths at 1318, 1064, and 946 nm corresponding
to energy transition states from the Stark levels of the
upper laser state
4
F
3/2
to three individual lower laser states
of
4
I
13/2
,
4
I
11/2
and
4
I
9/2
. However, the least energetic
Correspondence to: Y. Bai, Institute of Photonics and Photon-
Technology, Northwest University, Xi’an 710069, China. Email:
by@nwu.edu.cn
transition in the manifold
4
F
3/2
to
3
I
11/2
corresponds to
another wavelength at 1123 nm of ceramic Nd: YAG
[12]
. The
1123 nm laser has attracted particular interest of researchers
because of its wide applications in many special fields. For
example, it can be used as a pumping source for thulium
up-conversion fiber lasers to generate the laser emission
[13]
,
or for space remote sensing
[14]
. In addition, 1123 nm
laser can also be used to produce 561 nm yellow laser by
frequency doubling, which has become the ideal light source
in photodynamic therapy for cutaneous hemangioma and
micro-venous malformations
[12, 15–17]
.
At present, investigations on pulsed 1123 nm laser mainly
focus on passively Q-switched output based on saturable
absorber or self-mode-locked output. In 2016, Li et al. ob-
tained a passively Q-switched 1123 nm laser with a rep-
etition rate of 116 kHz, pulse width of 8 ns, and single-
pulse energy of 69 µJ by using 808 nm laser diode (LD)
end-pumped ceramic Nd: YAG and Cr
4+
: YAG saturable
absorber
[18]
. In 2017, Bai et al. reported a passively Q-
switched 1123 nm laser with a pulse repetition rate of
457 kHz, pulse width of 231 ns, and single-pulse energy
of 0.38 µJ by using 808 nm LD end-pumped ceramic Nd:
1