Sub-kHz linewidths of a dual-locked ICSRO VECSEL (Withdrawn by Authors)

Quantum squeezed states of light require laser systems exhibiting superior low intensity noise and quantum phase noise. Within this framework, optical parametric oscillators (OPOs) have demonstrated significant promise due to their ability to produce highly-correlated non-classical output photons. In a recent publication, we have illustrated the effectiveness of vertical external-cavity surface-emitting lasers (VECSELs) as pump sources for OPOs by achieving single-frequency operation with high stability. In this investigation, we present the first OPO device pumped by a frequency-locked VECSEL system (AlGaInP-based) and conduct a thorough evaluation of the noise characteristics of the OPO VECSEL, resulting in narrow integrated (1 s) linewidths (and intensity noise reductions) for the VECSEL fundamental (691 nm), signal (1.25 µm), and idler (1.55 µm) of 54.3 kHz (31.1 dB), 72.6 kHz (33.5 dB), and 25.3 kHz (18.3 dB), respectively. Further noise reduction will be investigated, via locking the OPO cavity, targeting reduced overall system noise compared to OPOs reported in the literature. Publisher’s Note: this conference presentation, originally published on 21 March 2025, was withdrawn 1 May 2025 per author request.