Theoretical and experimental studies of output coupling ratio tunable double-corner-cube-retroreflector ring cavity
Zhenguo Zhang, Youlun Ju
Abstract
The polarization state in a double-corner-cube-retroreflector (DCCR) ring cavity is analyzed using Jones matrix. Based on the analysis results, an output coupling ratio tunable DCCR ring cavity created by employing a polarization beam splitter, and wave plates (including <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>λ</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> plate and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>λ</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>4</mml:mn> </mml:mrow> </mml:math> plate) is studied theoretically and experimentally. The theoretical output coupling ratio tuning ranges are calculated as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>0.01</mml:mn> </mml:mrow> <mml:mi mathvariant="normal">%</mml:mi> <mml:mspace width="thickmathspace"/> <mml:mo>∼</mml:mo> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>80.86</mml:mn> </mml:mrow> <mml:mi mathvariant="normal">%</mml:mi> </mml:math> by rotating the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>λ</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> plate, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>0</mml:mn> </mml:mrow> <mml:mspace width="thickmathspace"/> <mml:mo>∼</mml:mo> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>89.32</mml:mn> </mml:mrow> <mml:mi mathvariant="normal">%</mml:mi> </mml:math> by rotating the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>λ</mml:mi> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>4</mml:mn> </mml:mrow> </mml:math> plate, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>2.71</mml:mn> </mml:mrow> <mml:mi mathvariant="normal">%</mml:mi> <mml:mspace width="thickmathspace"/> <mml:mo>∼</mml:mo> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>81.37</mml:mn> </mml:mrow> <mml:mi mathvariant="normal">%</mml:mi> </mml:math> by rotating corner-cube retroreflector (CCR). The experimental measurement results are consistent with theoretical expectations. An output coupling ratio tunable Er:YAG laser with a DCCR ring cavity is also set up to verify the beneficial effect of output coupling ratio tuning. At given pump power, by tuning the output coupling ratio, the laser obtains optimum operation efficiency and realizes wavelength conversion between 1645 and 1617 nm.