hide
Free keywords:
ENHANCED ABSORPTION-SPECTROSCOPY; SUPERCONTINUUM RADIATION; HEMOGLOBIN;
PHASE; CARBOXYHEMOGLOBIN; SPECTRA; WAVESChemistry;
Abstract:
We present a spectrometer for sensitive absorption measurements in liquids across broad spectral bandwidths. The spectrometer combines the unique spectral properties of incoherent supercontinuum light sources with the advantages of cavity ring-down spectroscopy, which is a self-calibrating technique. A custom-built avalanche photodiode array is used for detection, permitting the simultaneous measurement of ring-down times for up to 64 different spectral components at nanosecond temporal resolution. The minimum detectable absorption coefficient was measured to be 3.2 x 10(-6) cm(-1) Hz at 527 nm. We show that the spectrometer is capable of recording spectral differences in trace levels of blood before and after hemolysis.
