Quantum cascade laser-based sensing to investigate fast laser ablation process

We demonstrated a sensing technique for in-line ablation rate detection using a quantum cascade laser (QCL) under external optical feedback. The design of the QCL-based diagnostic system allowed to monitor the voltage modulation at the laser terminals induced by fast dynamics in the ablation process. Real-time detection of the ablation front velocity as well as in-situ investigations of the surface temperature were provided. Experimental results on fast ablation rates per pulse correlate well with the theoretical prediction. The detection range was demonstrated to be limited only by the QCL-probe emission wavelength, which is scalable up to the THz spectral region.

[1]  Guido Giuliani,et al.  Measurements of the alpha factor of a distributed-feedback quantum cascade laser by an optical feedback self-mixing technique. , 2006, Optics letters.

[2]  M. Phillips,et al.  Intracavity sensing via compliance voltage in an external cavity quantum cascade laser. , 2012, Optics letters.

[3]  Gaetano Scamarcio,et al.  Simultaneous measurement of multiple target displacements by self-mixing interferometry in a single laser diode. , 2011, Optics express.

[4]  Gaetano Scamarcio,et al.  Real time ablation rate measurement during high aspect-ratio hole drilling with a 120-ps fiber laser. , 2012, Optics express.

[5]  Guido Giuliani,et al.  Linewidth enhancement factor of terahertz quantum cascade lasers , 2008 .

[6]  Edmund H. Linfield,et al.  Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers , 2011 .

[7]  F. Capasso,et al.  Quantum cascade lasers in chemical physics , 2010 .

[8]  Francesco P. Mezzapesa,et al.  Laser ablation dynamics in metals: The thermal regime , 2012 .

[9]  Francesco P. Mezzapesa,et al.  Detection of ultrafast laser ablation using quantum cascade laser-based sensing , 2012 .

[10]  Yah Leng Lim,et al.  Terahertz imaging through self-mixing in a quantum cascade laser. , 2011, Optics letters.

[11]  Gaetano Scamarcio,et al.  High-resolution monitoring of the hole depth during ultrafast laser ablation drilling by diode laser self-mixing interferometry. , 2011, Optics letters.