BiB3O6 femtosecond optical parametric oscillator

Area of Science:

• Nonlinear Optics
• Laser Physics
• Materials Science

Background:

• Optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Femtosecond lasers enable high-precision measurements and material processing.
• Nonlinear optical crystals are key components in OPOs for frequency conversion.

Purpose of the Study:

• To demonstrate a femtosecond optical parametric oscillator (OPO) based on the nonlinear material Bismuth Borate (BiB3O6).
• To achieve wide and continuous spectral tuning across the visible range using a single crystal.
• To characterize the performance of the OPO in terms of tuning range, output power, and pulse duration.

Main Methods:

• Synchronous pumping of the OPO using the second harmonic of a Kerr-lens-mode-locked Ti:sapphire laser.
• Utilizing a 500 micrometer BiB3O6 crystal with collinear type I phase matching (e+e->o) in the optical yz plane.
• Employing angle tuning at room temperature to achieve spectral coverage.

Main Results:

• Demonstrated a signal wavelength tuning range from 480 nm to 710 nm (green-yellow-orange-red spectral range).
• Achieved average output powers of 270 mW.
• Obtained near-transform-limited signal pulses of 120 fs duration with 220 fs blue pump pulses at a 76 MHz repetition rate.

Conclusions:

• The BiB3O6-based OPO offers a versatile and efficient source for tunable femtosecond pulses.
• The demonstrated wide tuning range and short pulse durations are advantageous for various spectroscopic and nonlinear optical experiments.
• This OPO design represents a significant advancement in tunable ultrashort pulse generation.