Design of quasi-phasematching gratings via convex optimization

Area of Science:

• Nonlinear Optics
• Materials Science
• Computational Physics

Background:

• Quasi-phasematching (QPM) is crucial for efficient nonlinear optical frequency conversion.
• Traditional QPM design methods can be complex and may not yield globally optimal solutions.
• Advanced computational techniques are needed to address intricate QPM design challenges.

Purpose of the Study:

• To develop a novel, versatile framework for quasi-phasematching (QPM) design using convex optimization.
• To demonstrate the capability of finding globally optimum solutions for critical QPM design problems.
• To illustrate the application of convex optimization in synthesizing specific nonlinear optical functionalities.

Main Methods:

• Formulation of QPM design problems as convex optimization problems.
• Utilizing convex optimization solvers to determine globally optimum QPM structures.
• Application of the framework to three distinct nonlinear optical scenarios.

Main Results:

• Convex optimization provides a straightforward method to solve complex QPM design problems.
• Globally optimum solutions were achieved for synthesizing target pulse profiles via difference frequency generation (DFG).
• The approach successfully designed custom DFG transfer functions and enabled spectral gain narrowing suppression in optical parametric chirped pulse amplification (OPCPA).

Conclusions:

• Convex optimization offers a powerful and versatile tool for designing advanced QPM devices.
• This approach enables precise control over nonlinear optical processes, overcoming limitations of conventional methods.
• The demonstrated examples highlight the broad applicability and efficiency of convex optimization in QPM device engineering.