Highly efficient single-longitudinal-mode beta-BaB(2)O(4) optical parametric oscillator with a new cavity design

Area of Science:

• Nonlinear optics
• Laser physics
• Cavity design

Background:

• Optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Achieving single-longitudinal-mode operation in OPOs is essential for high-resolution spectroscopy and other applications.
• Conventional OPO cavity designs often face challenges in achieving stable single-mode output and efficiency.

Purpose of the Study:

• To introduce and analyze a new coupled-cavity design for optical parametric oscillators (OPOs).
• To demonstrate single-longitudinal-mode operation in an OPO system.
• To compare the performance of the new design against conventional OPO cavities.

Main Methods:

• The study utilizes a coupled-cavity design for an optical parametric oscillator.
• The OPO is constructed using a beta-barium borate (BBO) crystal.
• The system is pumped by the third harmonic of a Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser.

Main Results:

• The coupled-cavity design successfully achieved single-longitudinal-mode operation.
• A significant decrease in the oscillation threshold was observed.
• An increase in the external efficiency of the OPO was recorded compared to grazing-incidence designs.
• A mathematical model for the cavity mode spacings was developed.

Conclusions:

• The proposed coupled-cavity design offers a viable method for achieving single-longitudinal-mode operation in OPOs.
• This design presents advantages in terms of lower threshold and higher efficiency.
• The mathematical model provides a theoretical basis for understanding and optimizing the cavity performance.