BROAD-BAND COHERENT ANTI-STOKES-RAMAN SPECTROSCOPY WITH A MODELESS DYE-LASER

We develop a modeless dye laser for broadband coherent anti-Stokes Ram an spectroscopy (CARS) and investigate the operational characteristics of the modeless laser. The energy efficiency of the modeless laser is 6%, and the beam divergence is 0.65 mrad. We construct a compact mova ble CARS system with the modeless laser and a graphite tube furnace to assess the accuracy of the CARS temperature. It is found that the dif ference between the averaged CARS temperature and the radiation temper ature measured with an optical pyrometer is <2% at a temperature range from 1000 to 2400 K. We also measure the averaged CARS temperature dr ift owing to the variation of the spectral distribution of the modeles s laser, which is <1.5% during 5 h of operation. (C) 1997 Optical Soci ety of America.