Generation of new spatial and temporal coherent states using VECSEL technology: VORTEX, high order Laguerre-Gauss mode, continuum source

Abstract

Since years, the VeCSEL concept is pointed out as a technology of choice for beyond-state-of-the-art laser light sources. The targeted coherent state in CW is typically the common gaussian TEM 00 , single frequency, linearly polarized lightstate. In this work, we take advantage of the VeCSEL technology for the generation of other kinds of coherent states, thanks to the insertion of intracavity functions, such as low-loss intensity and phase filters integrated on a semiconductor chip. This technological development permitted to demonstrate very pure high-order Laguerre-Gauss mode, both degenerate and non-degenerate(vortex)modes, preserving the coherence properties of usual TEM 00 VeCSELs. This technology paves the way for the generation of other coherences (Bessel beams) or new functionnalities (wavelength filtering, etc.). We also explore new time domain coherence : owing to a high gain semiconductor chip design and the insertion of intracavity AOM, we demonstrated the first Frequecy-Shifted-Feedback VeCSEL, with a broadband coherence state as wide as 300 GHz.

Spatially Structured Optical Pump for Laser Generation Tuning

“…In addition, it is possible to shape the beam inside the cavity (“intracavity”), forcing certain modes to resonate and dominate over others. Due to the filtering nature of the resonator [ 25 , 26 , 27 , 28 ], this method of modulation is mostly used for mode selection where gain or loss can be spatially controlled to select the desired mode [ 29 , 30 , 31 , 32 , 33 , 34 ] of the laser output and obtain a higher energy extraction efficiency from the lasing medium [ 35 , 36 ] by using top-hat or flat-top beam profiles when the beam propagates through the gain region. Another benefit of intracavity modulation is the ability to form flat-top beams that are invariant under propagation.…”