Continuous-wave diode-laser injection-seeded beta-barium borate optical parametric oscillator: a reliable source for...

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Optics

Background:

• Optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Nd:YAG lasers and beta-barium borate (BBO) crystals are established components in laser systems.
• Seeding OPOs with diode lasers offers a method for precise wavelength control.

Purpose of the Study:

• To describe the development and performance of a beta-barium borate optical parametric oscillator.
• To investigate single longitudinal mode operation and its impact on linewidth.
• To evaluate the conversion efficiency and tuning characteristics of the seeded OPO.

Main Methods:

• Utilized a beta-barium borate (BBO) crystal as the nonlinear medium.
• Pumped the OPO using the third harmonic of a pulsed Nd:YAG laser.
• Employed a continuous-wave (cw) diode laser for seeding the OPO cavity.

Main Results:

• Achieved single longitudinal mode operation with a linewidth below 500 MHz (0.017 cm(-1)).
• Demonstrated a maximum conversion efficiency of 20% for the signal output.
• Identified the diode laser's tunability as the limiting factor for the seeded tuning range.

Conclusions:

• The developed BBO OPO provides a stable, narrow-linewidth, and efficient source of tunable laser light.
• Single longitudinal mode operation is successfully achieved through cavity design and seeding.
• Further improvements in tuning range depend on the development of broadly tunable seed lasers.