Low threshold, singly-resonant CW OPO pumped by an all-fiber pump source

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Optics

Background:

• Continuous-wave singly-resonant optical parametric oscillators (CW SROs) are crucial for generating tunable coherent light.
• Traditional CW SROs often require bulky and complex pump sources, limiting their practicality.
• Previous fiber-pumped CW SROs have faced challenges with high oscillation thresholds and broad linewidths.

Purpose of the Study:

• To demonstrate a novel CW SRO system utilizing an all-fiber pump source.
• To investigate the oscillation threshold and spectral characteristics of the developed SRO.
• To establish a new benchmark for fiber-pumped CW SRO performance.

Main Methods:

• Utilized a fiber-amplified, distributed feedback (DFB) fiber laser as the pump source for the CW SRO.
• Characterized the oscillation threshold, measuring it at 780mW.
• Measured the output linewidth and demonstrated idler frequency tuning via pump laser adjustment.

Main Results:

• Achieved a significantly reduced oscillation threshold of 780mW, a threefold decrease compared to previous 1-micrometer-pumped CW SROs.
• Demonstrated a narrow linewidth of 1MHz.
• Successfully fine-tuned the idler frequency by up to 130GHz through pump laser tuning.
• This represents the first single-frequency CW SRO pumped by an all-fiber source.

Conclusions:

• The developed all-fiber-pumped CW SRO offers a compact and efficient solution for tunable light generation.
• The system exhibits a remarkably low threshold and narrow linewidth, surpassing previous fiber-pumped SROs.
• This work paves the way for more accessible and versatile applications of CW SRO technology.