Stable, continuous-wave, intracavity, optical parametric oscillator pumped by a semiconductor disk laser (VECSEL)

Area of Science:

• Nonlinear optics
• Laser physics
• Solid-state devices

Background:

• Intracavity optical parametric oscillators (OPOs) offer efficient frequency conversion.
• Achieving continuous-wave (CW) operation free of relaxation oscillations is crucial for stable OPO performance.
• Semiconductor disk lasers (VECSELs) provide compact and efficient pump sources.

Purpose of the Study:

• To demonstrate relaxation oscillation-free, true continuous-wave (CW) operation of an intracavity optical parametric oscillator (OPO).
• To utilize a compact, optically-excited semiconductor disk laser (VECSEL) as the pump source for the OPO.
• To achieve high down-conversion efficiency in a low-threshold intracavity OPO system.

Main Methods:

• Constructed a singly-resonant intracavity OPO using periodically-poled, MgO-doped LiNbO3.
• Pumped the OPO internally within the cavity of a compact VECSEL.
• Optimized the system for low-power operation to achieve parametric threshold.

Main Results:

• Achieved parametric threshold at a low diode-laser power of 1.4 W.
• Demonstrated relaxation oscillation-free, true continuous-wave (CW) operation.
• Extracted 205 mW of idler power at 8.5 W pump power, yielding a 1.25 W total down-converted power.
• Attained a high down-conversion efficiency of 83%.

Conclusions:

• The combination of a VECSEL pump and a high-finesse cavity enables efficient, oscillation-free intracavity OPO operation.
• The developed OPO system offers a low-threshold, high-efficiency solution for CW frequency conversion.
• This work paves the way for compact and stable parametric light sources.