holder

The following is an abstract for the selected article. A PDF download of the full text of this article is available here. Members may download full texts at no charge. Non-members may be charged a small fee for certain articles.


Pump/Probe Thermal Lens Spectroscopy with Polarization-Encoded Laser Beams

Volume 39, Number 1 (Feb. 1985) Page 90-93

Pang, Teng-Ke Joseph; Morris, Michael D.


A new detection system for pump-and-probe thermal lens spectroscopy has been developed. Two orthogonally polarized beams derived from the same CW laser serve as pump and probe. The pump beam is chopped and recombined with the probe laser. A Glan prism located after the absorption cell separates pump-and-probe beams. The thermal lens is sensed as the probe beam overflows a limiting aperture and is processed through a lock-in amplifier. The thermal lens response is linear in analyte concentration. The system is applied to liquid chromatography detection. The noise level is about 4 microabsorbanee rms. Once aligned, the system remains in alignment indefinitely, since laser pointing instabilities cancel.