Electric-field-induced second harmonic generation in silicon dioxide.

Area of Science:

• Nonlinear Optics and Photonics
• Materials Science for Functional Devices
• Solid-State Physics

Background:

• Electric-field-induced second harmonic generation (EFISH) is a third-order nonlinear optical process.
• EFISH is crucial for developing advanced nonlinear optical structures, particularly for background-free electro-optical sampling.
• Materials with vanishing second-order susceptibility (χ(2)) and non-zero third-order susceptibility (χ(3)) are ideal for EFISH applications.

Purpose of the Study:

• To investigate silicon dioxide (SiO2) as a potential material for EFISH applications.
• To demonstrate and quantify EFISH in SiO2 under applied DC electric fields.
• To explore the feasibility of using SiO2 for background-free nonlinear optical phenomena.

Main Methods:

• Experimental investigation of SiO2 using high DC electric fields.
• Excitation of the material at a fundamental wavelength of 800 nm.
• Time-domain simulations to model the observed EFISH signal.

Main Results:

• Significant second harmonic generation (SHG) was observed in SiO2, clearly distinguishable from background signals.
• The generation of a SHG signal at 400 nm from an 800 nm fundamental excitation confirmed EFISH.
• Accurate modeling of the EFISH signal was achieved using time-domain simulations.

Conclusions:

• Silicon dioxide (SiO2) exhibits significant electric-field-induced second harmonic generation (EFISH) under applied DC electric fields.
• The observed EFISH in SiO2 validates its potential for applications in nonlinear optics.
• Time-domain simulations provide a valuable tool for optimizing EFISH efficiency and guiding future device design.