A novel and compact near-infrared (NIR) Raman system is developed using 785-nm diode laser, volume-phase technology (VPT) holographic system, and NIR intensified charge-coupled device (CCD). Signal-to-noise ratio (SNR) and resolution are improved compared with ordinary acquisition method by a specially designed optical fiber detector and the spectrograph image aberration correction with a parabolic-line fiber array. In 1-5 s, Raman spectra of different parts of Chinese human skin are acquired. Autofluorescence is subtracted from the raw spectrum by polynomial fitting and skin Raman spectrum is then smoothed for further analysis.
© 2007 Chinese Optics LettersPDF Article