Compact low-threshold Q-switched intracavity optical parametric oscillator.

Area of Science:

• Photonics and Laser Technology
• Nonlinear Optics
• Materials Science

Background:

• Intracavity optical parametric oscillators (OPOs) offer efficient wavelength conversion.
• Microchip laser designs provide compact and robust laser sources.
• Potassium Titanyl Phosphate (KTiOPO4 or KTP) is a widely used nonlinear optical crystal.

Purpose of the Study:

• To develop a compact, low-threshold singly resonant pulsed intracavity optical parametric oscillator.
• To investigate the performance of a novel quadrupole deflector Q switch in a microchip laser design.
• To achieve efficient generation of tunable, single-frequency infrared pulses.

Main Methods:

• Utilized a semi-monolithic microchip laser design incorporating a KTiOPO4 crystal.
• Employed a novel quadrupole deflector Q switch for pulsed operation.
• Pumped the system with a 2-W laser diode at 1.064 microm.

Main Results:

• Achieved a low threshold of 1.3 W for the optical parametric oscillator.
• Generated 0.4-microJ signal pulses with 5.6-ns duration at 1.53 microm.
• Obtained diffraction-limited, single-frequency signal pulses at a 5 kHz repetition rate.

Conclusions:

• The developed intracavity OPO demonstrates high efficiency and compactness.
• The novel Q switch design enables low-threshold, high-quality pulse generation.
• This compact OPO system is suitable for applications requiring tunable, single-frequency infrared light.