How does nonlinear optics work?
Nonlinear optics arises when intense light, such as from a laser, interacts with a material and the response is no longer proportional to the electric field. The polarization becomes a series of terms: P = χ¹E + χ²E² + χ³E³ + ... . The second-order term, χ², enables frequency doubling—converting red light to blue. The third-order term, χ³, allows effects like the Kerr effect and four-wave mixing. I developed the theoretical framework for these processes, emphasizing that coherence is fragile but essential for quantum control. Experimentally, we must check conditions like phase matching to maximize efficiency. It's a beautiful interplay of theory and measurement.
Ask Nicolaas Bloembergen the follow-up →