Broadband sum frequency generation via chirped quasi-phase-matching

TL;DR

This paper introduces a broadband sum frequency generation method using chirped quasi-phase-matching gratings, enabling efficient energy transfer through an adiabatic process analogous to quantum state transfer.

Contribution

It proposes a novel broadband SFG technique with chirped gratings that mimics adiabatic population transfer, enhancing efficiency and control in nonlinear optical processes.

Findings

Achieves efficient broadband SFG with chirped gratings.

Demonstrates adiabatic energy transfer analogous to quantum systems.

Effective even in the nonlinear regime with pump depletion.

Abstract

An efficient broadband sum frequency generation (SFG) technique using the two collinear optical parametric processes \omega 3=\omega 1+\omega 2 and \omega 4=\omega 1+\omega 3 is proposed. The technique uses chirped quasi-phase-matched gratings, which, in the undepleted pump approximation, make SFG analogous to adiabatic population transfer in three-state systems with crossing energies in quantum physics. If the local modulation period %for aperiodically poled quasi-phase-matching first makes the phase match occur for \omega 3 and then for \omega 4 SFG processes then the energy is converted adiabatically to the \omega 4 field. Efficient SFG of the \omega 4 field is also possible by the opposite direction of the local modulation sweep; then transient SFG of the \omega 3 field is strongly reduced. Most of these features remain valid in the nonlinear regime of depleted pump.