# Background-Free Fourth-Order Sum Frequency Generation Spectroscopy

> Research article (The Journal of Physical Chemistry Letters, 2015) · cited 16× · AI/ML

**Wikidata**: [openalex:W750282618](https://www.wikidata.org/wiki/openalex:W750282618)  
**Source**: https://4ort.xyz/entity/background-free-fourth-order-sum-frequency-generation-spectroscopy