Frequency-doubling of continuous laser light in Laguerre–Gaussian modes LG_0,0 and LG_3,3

authored by

Joscha Heinze, Henning Vahlbruch, Benno Willke

Abstract

For future generations of gravitational wave detectors, it is proposed to use the helical Laguerre–Gaussian LG₃₃ mode to reduce thermal noise, which limits the detector sensitivity. At the same time, this requires the efficient generation of squeezed vacuum states in the LG₃₃ mode for quantum noise reduction. Since this technique includes the process of second harmonic generation (SHG), we experimentally compare the conversion efficiency and harmonic output field of the LG₀₀ and LG₃₃ modes in a cavity-enhanced SHG using the same 7% doped MgO:LiNbO₃ crystal. Conversion efficiencies of 96% and 45% are achieved, respectively. The influence of mode mismatches and astigmatism is analyzed to estimate the ratio of the pump mode-dependent effective nonlinearities to be d₀₀/d₃₃ ∼ 5. Furthermore, we show that absorption loss in the crystal is more relevant for the LG₃₃ mode.

Organisation(s)

Institute of Gravitation Physics
QuantumFrontiers

External Organisation(s)

Max Planck Institute for Gravitational Physics (Albert Einstein Institute)

Type

Article

Journal

Optics letters

Volume

45

Pages

5262-5265

No. of pages

4

ISSN

0146-9592

Publication date

15.09.2020

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics

Electronic version(s)

https://doi.org/10.1364/OL.402371 (Access: Open)
https://doi.org/10.1364/OL.410805 (Access: Open)