Broadband light source using an extended cavity tapered laser with volume Bragg grating

Abstract We have developed a broadband light source based on an extended-cavity tapered amplifier, whose frequency is stabilized using a volume Bragg grating (VBG). The setup delivers up to 200 $$\text {mW}$$ of optical power over the 14640–14670 $$\text {cm}^{-1}$$ range, with a spectral bandwidth of about 2 $$\text {cm}^{-1}$$ . We have characterized the source as a function of both the VBG angle and the tapered amplifier drive current, using a home-built virtually imaged phased array (VIPA) spectrometer. To demonstrate its capabilities, we carried out iodine absorption spectroscopy in the 14664.5–14666.5 $$\text {cm}^{-1}$$ interval. This broadband source is promising for a variety of applications, in particular for cooling the translational, vibrational, and rotational degrees of freedom of diatomic molecules.