Probing electric fields in semiconductor devices using electric field induced second harmonic generation

We observe electric field induced second harmonic generation in a GaN based UV diode laser. The scattered second harmonic is collected and measured as a function of bias voltage and incident laser power. We observe bulk electric field induced second harmonic generation from the active region of a GaN UV diode laser (Nichia). By probing at one half the bandgap using a Ti:sapphire laser, we can still take advantage of resonant enhancement of the semiconductor bandgap while reducing absorption (invasiveness) and allowing penetration into the device. Ultimately, we hope to use this technique to probe silicon-based integrated circuits using infrared light.