Mixed gas sensing based on superluminescent diode (SLED) with Fabry-Perot etalon and vibrational coherent anti-Stokes Ramen spectroscopy (CARS) technique with single Nd^: YAG laser for mixed gases like C_2H_2 CO_2 and CH_4 /CO_2 are compared for combustion applications. With a sample cell filled with gas mixtures, the SLED technique provides low cost, selective gas sensing for exhaust emission measurements whereas the CARS technique with Ramen shifter, provides coherent output with simplified experimental set up compared to conventional CARS. The planner BOX-CARS arrangement, used for flame measurement reduces non-resonance information. The measurement of temperature along with concentration is to be studied to use this CARS technique for combustion applications. Papers reported in the 9th International Symposium on "Novel Carbon Resource Sciences" Nov. 2-3, 2012