Widely tunable cavity-enhanced backward difference-frequency generation
Abstract
Difference-frequency generation (DFG) is a powerful technique for generating widely tunable infrared radiation. However, conventional phase-matching schemes may require tuning multiple parameters-such as the wavelengths, crystal temperature, crystal angle, and poling period-to achieve wide tunability, which increases the complexity of practical operation. In this work, we employ a backward quasi-phase-matching scheme with distinctive tuning characteristics and demonstrate pump-enhanced continuous-wave DFG output tunable from 1751 nm to 2451 nm (700 nm range) in a bulk crystal. The tuning is achieved solely by varying the pump wavelength and the signal wavelength (less than 5 nm), enabling continuous, rapid, and room-temperature operation. The tuning characteristics, power-scaling behavior, and output stability are experimentally verified with the idler wavelength set at 2000 nm. The approach offers a new paradigm for widely tunable infrared radiation generation and holds promise for applications in spectroscopy and biomedical sensing.
Keywords
Cite
@article{arxiv.2510.15539,
title = {Widely tunable cavity-enhanced backward difference-frequency generation},
author = {Ming-Yuan Gao and Yue-Wei Song and Ren-Hui Chen and Yin-Hai Li and Zhi-Yuan Zhou and Bao-Sen Shi},
journal= {arXiv preprint arXiv:2510.15539},
year = {2025}
}