High repetition-rate wavelength tuning of an extended cavity diode laser for gas phase sensing

A method for rapid wavelength tuning of an extended cavity diode laser (ECDL) is presented providing for high resolution, narrow bandwidth output over limited spectral regions. The method permits tuning over isolated spectroscopic features at repetition rates of tens of kHz, greatly exceeding conventional ECDL tuning speeds. In this paper we present high repetition rate laser induced fluorescence (LIF) spectroscopy of the 5²P_1/2 to 6²S_1/2 transition in indium at 410 nm, to demonstrate the technique. The presented ECDL design is very easy to implement, cheap and robust, as it employs no moving parts and can be used over all wavelength regions where FP diode lasers are available. This extends the usefulness of standard FP diode lasers to high speed sensing applications. Advantages and disadvantages of the technique are discussed. PACS 42.55.Px; 42.60.Fc; 42.62.Fi; 32.50.+d