| 摘要 |
Apparatus for detecting a chemical vapor species, comprising a micro-cavity having a first resonant frequency corresponding to the absorption wavelength of the species and a second resonant frequency, an ambient area surrounding the micro-cavity for receiving the species, a source for directing a mid- to far-infrared pump beam having a resonant mode coincident with the first frequency into the micro-cavity, a source for directing a near-infrared probe beam tuned to the second resonant frequency into the micro-cavity, and detectors for detecting the probe beam after transmission through the micro-cavity. The pump beam induces optical absorption by the vapor species, causing photothermal effects in the micro-cavity to shift the second resonant frequency. A processor identifies and correlates the wavelength shift to a characteristic photothermal signal for the chemical vapor species. Apparatus for detecting multiple species and methods for detecting single or multiple species are also disclosed. |
