摘要 |
A particle detector employs a laser having a solid-state lasing medium, such as an Nd:YAG crystal, disposed in a resonant cavity, and includes an intracavity view volume. The resonant cavity is defined by two spaced apart mirrors, with the laser medium positioned between them, defining a light path. A pump source is optically coupled to drive the laser medium to produce coherent light having a first wavelength. The view volume is positioned in the light path, between the first mirror and the laser medium, to introduce particles into the resonant cavity so that light impinging there-upon produces scattered light. A detector is disposed to sense light scattered from the view volume and produces signals proportional to the light sensed. A displaying device, such as a pulse height analyzer, is in electrical communication to receive the signals produced by the detector to quantitatively display the intensity of the light sensed. In an alternate embodiment, a harmonic generator is disposed within the light path to shorten the wavelength of light impinging upon particles in the view volume, making the detector more sensitive to particles of sub-micron size.
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