A QEPAS-Based Central Wavelength Stabilized Diode Laser for Gas Sensing

A quartz-enhanced photoacoustic spectroscopy-based central wavelength stabilized distributed feedback diode laser is demonstrated in this letter. A quartz tuning fork is used as a sharp transducer to generate an error signal for wavelength tuning and stabilization without photodetector, which contributes to low cost, compact size, and freedom from ambient acoustic noises. The central wavelength of the diode laser obtains quickly fine-tuning at various modulation depths because it varies in time with the driving current. The wavelength stability of the diode laser is thus enhanced effectively. The wavelength stabilized diode laser is suited for absorption spectroscopy-based gas sensors.