High-intensity nanosecond photorefractive spatial solitons

Area of Science:

• Nonlinear optics
• Solid-state physics

Background:

• Optical solitons are self-reinforcing light beams that maintain their shape while propagating.
• Strontium barium niobate (Sr$_{0.61}$Ba$_{0.39}$)Nb$_2$O$_6$ is a photorefractive crystal with potential for nonlinear optical applications.

Purpose of the Study:

• To experimentally observe and characterize high-intensity optical solitons in a bulk strontium barium niobate crystal.
• To compare experimental results with theoretical predictions for soliton behavior.

Main Methods:

• Utilized 8-ns pulsed laser with optical intensities exceeding 100 MW/cm$^2$.
• Observed soliton formation and dynamics within the bulk strontium barium niobate crystal.
• Measured soliton width evolution over multiple pulse interactions.

Main Results:

• Successfully observed high-intensity optical solitons in the strontium barium niobate crystal.
• Solitons reached minimum width after approximately ten pulses.
• Solitons achieved e$^{-1}$ of steady-state width after the first pulse.
• Experimental observations showed good agreement with theoretical predictions for the soliton existence curve.

Conclusions:

• High-intensity optical solitons can be generated and sustained in bulk strontium barium niobate.
• The dynamics of soliton formation and stabilization are well-described by existing theoretical models.
• This work validates strontium barium niobate as a suitable medium for studying nonlinear optical phenomena like soliton propagation.