Pump and thermal impact on heavily erbium-doped fiber laser generation
A. M. Smirnov, Oleg V. Butov
Abstract
A detailed comparative study of heavily erbium-doped fiber laser generation features was carried out in the case of 1490 nm and 976 nm wavelength pumping. The laser cavity was designed using point-by-point fiber Bragg grating inscription technology with femtosecond laser pulses. The CW and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi>Q</mml:mi> </mml:mrow> </mml:mrow> </mml:math> -switched lasing regimes were achieved depending on temperature and heat sink performance. It was found experimentally for the first time, to the best of our knowledge, that the frequency and pulse duration of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi>Q</mml:mi> </mml:mrow> </mml:mrow> </mml:math> -switched laser operations are primarily determined by the output laser power and do not depend on the pump wavelength. The pulse formation is caused by the lasing process itself and depends on the up-conversion rate at the generation wavelength. Additionally, the level of laser cavity heating at the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi>Q</mml:mi> </mml:mrow> </mml:mrow> </mml:math> -switched generation regime was defined.