Highly efficient mirrorless optical parametric oscillator pumped by nanosecond pulses.

Area of Science:

• Nonlinear Optics
• Laser Physics
• Materials Science

Background:

• Optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Conventional OPOs often face limitations in efficiency and spectral purity.
• Mirrorless OPOs offer a simplified and potentially more efficient alternative.

Purpose of the Study:

• To demonstrate a highly efficient mirrorless optical parametric oscillator (MOPO).
• To investigate the performance of a MOPO utilizing counter-propagating photons.
• To achieve high energy output with narrow spectral bandwidths.

Main Methods:

• Utilizing a 1-mm-thick periodically poled Rb-doped KTiOPO4 crystal.
• Employing quasi-phase-matched parametric interaction of counter-propagating photons.
• Pumping the MOPO with narrowband nanosecond pulses at 1064 nm.

Main Results:

• Achieved mJ-level output with a total signal-and-idler conversion efficiency of 47%.
• Generated a co-propagating signal at 1740 nm and a counter-propagating idler at 2741 nm.
• Observed narrow spectral bandwidths in both generated waves due to the nonlinear interaction.

Conclusions:

• The demonstrated MOPO is a highly efficient laser source.
• The counter-propagating nonlinear interaction enables narrow spectral bandwidths.
• This MOPO design presents an attractive alternative to conventional OPOs due to its efficiency and simplicity.