Single-longitudinal-mode cascaded crystalline Raman laser at 1.7 µm
Hui Zhao, Zhihua Tu, Shibo Dai, Siqi Zhu, Hao Yin, Zhen Li, Zhenqiang Chen
Abstract
A single-longitudinal-mode crystalline Raman laser in the 1.7 µm wave band was reported for the first time, to the best of our knowledge. The <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">Y</mml:mi> <mml:mi mathvariant="normal">V</mml:mi> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mn>4</mml:mn> </mml:msub> </mml:mrow> </mml:math> Raman laser, which was intracavity-pumped by an actively <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>Q</mml:mi> </mml:math> -switched 1314 nm Nd:YLF laser, demonstrated the cascaded Stokes oscillation at 1715 nm. By inserting an etalon in the fundamental resonator, linewidth narrowing and power scaling of the second-Stokes laser were realized based on the spatial-hole-burning-free Raman gain. With an optimal pulse repetition frequency of 4 kHz, the maximum single-longitudinal-mode average output power of 1.8 W was acquired with the spectrum linewidth of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>∼</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>340</mml:mn> </mml:mrow> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">M</mml:mi> <mml:mi mathvariant="normal">H</mml:mi> <mml:mi mathvariant="normal">z</mml:mi> </mml:mrow> </mml:math> . Further increasing the incident pump power, the second-Stokes laser transitioned to multimode regime, and the maximum average output power reached 2.7 W with the peak power as high as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>∼</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>380</mml:mn> </mml:mrow> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">k</mml:mi> <mml:mi mathvariant="normal">W</mml:mi> </mml:mrow> </mml:math> .