Abstract: Multi-dimensional Rydberg fingerprint spectroscopy can be used for chemical sensing in gaseous mixtures. A pulsed laser beam having a first wavelength can be delivered to a sample using a tunable pulsed excitation laser; and a pulsed laser beam having a second wavelength can be delivered to the sample point using a tunable pulsed transition laser. The pulsed laser beam having the first wavelength and the pulsed laser beam having the second wavelength have energy sufficient to excite an electron of a sample molecule to a Rydberg state. A level of ionization or light absorption can be detected at the sample point. The level of ionization or light absorption detected and the first and second wavelengths are used to determine the presence and identity of one or more chemicals in the sample of the gaseous mixture.

Abstract: A protective ear covering has a self-fastening strap to fasten to the goggle strap of ski goggles or to a fabric headband. The ear protector's outer edge includes wedge-shaped riser to accommodate an ear's outward projection, while the inside rim of the protector, circumscribed by a deformable gasket, rests flat against a wearer's head. There is preferably an inner liner for warmth and comfort, and vents for ventilation and sound penetration are provided.