Description
In recent years, the interaction between strong-field laser and semiconductor materials has attracted widespread attention due to its potential in ultrafast optoelectronics and bandgap engineering. Among various semiconductors, silicon (Si) offers significant advantages, including natural abundance, mature processing technology, ease of integration, and low cost, making it an ideal platform for investigating strong-field physics. When interacting with intense laser fields, silicon exhibits numerous novel physical phenomena. In this work, based on solid-state sideband harmonic technology, we observe for the first time the characteristics of even-order harmonics generated from centrosymmetric single-crystal silicon under strong-field excitation. We systematically investigate the influence of the pump frequency and the pump-probe time delay on the yield of these even-order harmonics. Furthermore, we analyze the differences in the even-order harmonic signals between single-crystal and amorphous silicon, under various excitation conditions, and across different sample thicknesses. This study provides new experimental evidence for understanding the optical response and bandgap regulation mechanisms of materials in the strong-field regime.
