Absolute frequency stabilization of an injection-seeded optical parametric oscillator

Area of Science:

• Optics and Photonics
• Laser Physics
• Spectroscopy

Background:

• Optical parametric oscillators (OPOs) are vital sources for tunable laser light.
• Precise frequency control of OPO output is essential for many scientific applications.
• Existing methods often lack absolute calibration and fine-tuning capabilities.

Purpose of the Study:

• To develop and demonstrate a method for absolute frequency stabilization and calibration of OPO signal and idler waves.
• To improve the accuracy and reliability of tunable laser sources.
• To enable precise frequency control over a wide tuning range.

Main Methods:

• Utilized a Helium-Neon (He-Ne) stabilized transfer cavity (TC) for frequency reference.
• Employed a He-Ne stabilized TC to control seeding laser frequencies for both the pump laser and OPO cavity.
• Incorporated an acousto-optic modulator (AOM) to tune the OPO seed laser frequency before locking to the TC.

Main Results:

• Achieved absolute frequency stabilization and calibration of OPO signal and idler waves.
• Demonstrated a residual frequency error of ±25 MHz for pump, signal, and idler waves.
• The achieved stability is approximately 30% of the 160 MHz linewidth of the OPO pulses.

Conclusions:

• The described method provides robust absolute frequency stabilization and calibration for injection-seeded OPOs.
• The technique allows for stabilization at any frequency by tuning the AOM sidebands.
• This advancement offers enhanced precision for tunable laser sources in scientific research.