SENSITIVE LASER SPECTROSCOPIC DETECTION BASED ON THREE-DIMENSIONAL NONLINEAR FOUR-WAVE MIXING

摘要

Devices and techniques for performing spectroscopic measurements in a sample vapor by using a four-wave-mixing optical system. A spectrometer (100) comprises a gas-phase atomizer (130) to vaporize a sample solution to produce a sample vapor, first and second alignment templates (120, 122) having apertures to align a probe beam (111P), first and second pump beams (111B, 111F) to form a four-wave mixing configuration, a laser (102) tunable to generate a laser beam (103) at a desired wavelength corresponding to an absorption line in the sample vapor, and optical elements (108, 110) disposed relative to the laser (102) and the atomizer (130) to split the laser beam (103) into a probe beam (111P) and the first and second pump beams (111B, 111F). The probe beam (111P), the first and second pump beams (111B, 111F) are directed to overlap with one another in the sample vapor to produce a signal beam (111S) through a four-wave mixing process.