The performance of an external cavity diode laser based noise immune cavity enhanced optical heterodyne molecular spectrometer is presented. To reduce the noise on the signal a ring cavity and a circuit to remove residual amplitude modulation on the pre-cavity laser radiation was implemented. We demonstrate a sensitivity of 4 x 10(-11) cm(-1) Hz(-1/2) using a cavity with a finesse of 2600 on a Doppler-broadened transition of CH(4) at 6610.063 cm(-1).
Keywords:
Computer-Aided Design
,Equipment Design
,Equipment Failure Analysis
,Lasers, Semiconductor
,Reproducibility of Results
,Sensitivity and Specificity
,Transducers
