Efficient Noncollinear Second-Harmonic Generation in Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ Crystals Through...

Area of Science:

• Nonlinear optics
• Materials science
• Photonics

Background:

• Non-collinear phase matching (PM) is crucial for broadband frequency conversion in all-optical signal processing.
• Perovskite ferroelectric materials offer potential for broadband second-harmonic generation (SHG) but suffer from scattering losses due to random domain structures.
• Existing methods face stringent requirements for quasi-phase-matching, limiting practical applications.

Purpose of the Study:

• To engineer a nonlinear photonic crystal with a regular domain structure for efficient broadband second-harmonic generation (SHG).
• To overcome the limitations of random domain distributions and scattering losses in ferroelectric materials.
• To demonstrate a tunable, efficient, and application-friendly frequency conversion technique.

Main Methods:

• Fabrication of a nonlinear photonic crystal using a Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystal.
• Construction of a domain structure with regularly distributed polarization vectors.
• Characterization of second-harmonic generation (SHG) efficiency and spectral bandwidth.

Main Results:

• Achieved broadband SHG with increased efficiency (6 × 10⁻⁵) for fundamental wavelengths from 1064 to 1340 nm.
• Demonstrated efficient SHG without the need for angle or temperature tuning.
• Observed spontaneous deviation of SHG emission from fundamental light propagation, simplifying detection.

Conclusions:

• Engineered domain structures in ferroelectrics provide a new pathway for broadband, efficient non-collinear SHG.
• This approach overcomes scattering losses and simplifies detection, advancing frequency conversion techniques.
• The developed nonlinear photonic crystal has significant potential for all-optical signal processing applications.