摘要 |
A thermal lens detection apparatus comprising: i) an optical cell for containing at least one target analyte present in a carrier liquid, ii) a probe beam having a pre-determined wavelength, iii) an excitation beam having a pre-determined wavelength shorter than that of the probe beam and a Rayleigh length approximately equal to the radius of said optical cell, the beam axis of said probe beam and the beam axis of said excitation beam being at an angle to each other but both the probe beam and excitation beam being focusable so that their beams overlap in the interior portion of the optical cell, iv) a signal photo-detector for receiving at least a portion of said probe beam signal after its passage through said optical cell, and iv) an optical cutoff filter which blocks the excitation beam from impinging on said signal photo-detector. |