Researchers at NIST are developing a new method called dual electro-optic frequency comb (DOFC) to improve the sensitivity and speed of detecting molecules using terahertz (THz) waves. This technique uses phase-coherent chirped light pulses to generate highly stable THz frequency combs. These combs are then converted into radiofrequency (RF) signals, which can be used to study the unique spectral features of molecules like formic acid. The method reduces phase noise, leading to clearer and more accurate measurements.
The system is being improved by using lasers near 1570 nm instead of 850 nm, which will significantly increase the THz power generated. Additionally, a new cryostation allows for experiments at a wide range of temperatures, from very cold (4 K) to room temperature (350 K). These advancements are expected to enhance the ability to study molecular behavior in different conditions, with potential applications in chemical sensing and material analysis. The technology is currently under development and testing, with promising results already demonstrated in laboratory settings.
Keywords: THz spectroscopy, electro-optic frequency comb, photomixer
