Molecular ions have long been considered key intermediates in the evolution of molecular
complexity in the interstellar medium. However, owing to their reactivity and transient nature …

Rapid, on-site diagnostics allow for timely intervention and response for warfighter support,
environmental monitoring, and global health needs. Portable optical biosensors are being …

A compact cavity ring-down spectrometer aimed at the detection of trace amounts of
radiocarbon (14 C) in biomedical samples is demonstrated. Rapid sampling, as required for …

A sensitive high-resolution sub-Doppler detecting spectrometer, based on noise-immune
cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS), for trace gas …

Raman scattering spectroscopies are important analytical tools in modern chemistry. Here,
we describe the construction of the unamplified Raman scattering analysis (URSA) …

A sub-Doppler rovibrational spectroscopic survey of H 3+ has been conducted which
included 36 transitions in the ν 2← 0 fundamental band, 15 transitions in the 2 ν 2 2← ν 2 …

A trace acetylene (C2H2) detection system was demonstrated using the cavity-enhanced
absorption spectroscopy (CEAS) technique and a near-infrared distributed feedback (NIR …

We demonstrate a new method for elemental mercury sensing by wavelength modulation
spectroscopy (WMS) using a tunable ultraviolet laser generated through a process of …

The saturated absorption spectrum of the hyperfineless S (0) quadrupole line in the (2-0)
band of H2 is measured at λ= 1189 nm, using the NICE-OHMS technique under cryogenic …

This thesis presents significant advancements in precision spectroscopy of molecular
hydrogen (H₂) and its isotopologues HD and HT by implementing Noise-Immune Cavity …