Absorption spectra of dye solutions measured using a white light thermal lens spectrophotometer.
We describe a two-beam thermal lens spectrophotometer that uses a xenon lamp as the excitation source and a low power diode pumped Nd-YAG laser as the probe light. The white light from the xenon source is filtered using a variable interference filter producing a partial monochromatic light within the spectral range 400-700 nm and with a spectral resolution of 10 nm. We measure the thermal lens spectrum of a nonfluorescent dye (Malachite Green) and show that this spectrum reproduces its absorbance spectra measured by the usual transmission method. A comparison of the thermal lens and the absorbance spectra of a fluorescent dye (Rhodamine B) reveals substantial differences. These differences can yield important applications of the device for the characterization of fluorescent materials.
Marcano O
A
A
Applied Optics Center, Delaware State University, Dover, Delaware 19901, USA. marcano@pion.ivic.ve
Ojeda
J
J
Melikechi
N
N
D004396:Coloring Agents / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D008029:Lighting / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods
D004396:Coloring Agents; D012996:Solutions