Real-time dynamic control of laser modes
Presented by Mr. Sandile NGCOBO on 5 Sep 2013 from 12:40 to 13:00
Adaptive optics has been used in many optical systems to correct the amount of wavefront distortionsfor application such aslaser ranging, free space optical communication and medical imaging of retinas. In these optical systems the correction of the wavefront is usually performed using deformable mirrors wherea wavefront sensor is typically used to measure the distortions the atmosphere has introduced on the timescale of a few milliseconds. The optimal mirror shape for correcting the distortions is then calculated using a computer and thesurface of the deformable mirror will then be reshaped accordingly.The reshaping of the mirror has been shown to have a limited stroke in the phase profiles that it can accommodate and thus have found little application in laser mode shaping. We have overcome this limitation with the first digital laser comprising an electrically addressed reflective phase-only spatial light modulator (SLM) as an intra-cavity holographic mirror where the amplitude and phase of the mirror are controlled by writing a new computer generated gray scale image on the SLM. We demonstrate that a digitally controlled digital laser for on-demand laser mode can be used to generate distortion-corrected laser modes by switching between several spatial modes in a standard solid state laser resonator.
Location: STIAS Conference Centre
Address: Stellenbosch Institute for Advanced Study Wallenberg Research Centre 10 Marais Road Stellenbosch South Africa www.stias.ac.za