Carving out configurable ultrafast pulses from a continuous wave source via the optical Kerr effect

Area of Science:

• Ultrafast Optics and Photonics
• Nonlinear Fiber Optics
• Femtosecond Spectroscopy

Background:

• Time-resolved measurements demand precisely controlled ultrafast optical pulses.
• Generating wavelength-tunable, time-locked pulse sequences is technically challenging.
• Existing methods often lack intrinsic timing stability and phase coherence.

Purpose of the Study:

• To demonstrate a simple method for generating configurable optical pulse sequences.
• To achieve wavelength tunability and precise timing control in ultrafast pulses.
• To develop an ultrafast light source with inherent stability and phase coherence.

Main Methods:

• Utilized pump-induced optical Kerr switching in a 10 cm commercial single-mode fiber.
• Carved sub-picosecond pulses from a continuous wave laser.
• Introduced dispersion to the pump beam to tune pulse duration (305-570 fs).
• Generated two- and four-pulse trains using birefringent alpha-BBO plates.

Main Results:

• Successfully generated tunable, near transform-limited ultrafast optical pulses.
• Achieved controllable pulse durations between 305 and 570 femtoseconds.
• Demonstrated the generation of multi-pulse sequences (two- and four-pulse trains).
• Confirmed intrinsic timing stability and pulse-to-pulse phase coherence.

Conclusions:

• The demonstrated method offers a simple and effective way to generate configurable ultrafast pulse sequences.
• This technique provides an ultrafast light source with high timing stability and phase coherence.
• The pulse generation approach is adaptable to a wide range of wavelengths (UV to IR).