Patent ID: 7036979

Claim:
A photothermal spectroscopic analyzer in which a probe light is incident on a thermal lens generated in a sample by incidence of an excitation light, and for analyzing the sample on the basis of a change in the probe light by the thermal lens in that case, comprising: a light source of the excitation light which comprises semiconductor laser beam-emitting means; a light source of the probe light which comprises another semiconductor laser beam-emitting means, wherein a condenser lens which focuses the excitation light in the sample and a condenser lens which focuses the probe light in the thermal lens are made to be a common lens; at least one detection means of detecting a change in the probe light by the thermal lens; and rounding means between at least the light source of the excitation light or the light source of the probe light, wherein the condenser lens brings the cross sectional geometry of at least one semiconductor laser beam emitted from the light sources into approximately the shape of a circle, wherein, when a transmission means, for allowing a part of the probe light which is changed by the thermal lens transmit, is provided between the sample and the at least one detection means, a distance in a direction of an optical axis between the transmission means and the sample is set at 10 cm or less, and a distance in the direction of an optical axis between the at least one detection means and the sample is set at 10 cm or less when a transmission means is not provided, and further a beam diameter in focal points of the excitation light and the probe light which are focused with the condenser lens, is 0.2 to 50 μm.