Bochum 2015 – scientific programme

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K: Fachverband Kurzzeitphysik

K 4: Lasersysteme und deren Anwendungen II

K 4.1: Talk

Tuesday, March 3, 2015, 14:00–14:20, HZO 40

Intracavity phase and amplitude manipulation of a femtosecond semiconductor laser system — •Rouven H. Pilny, Benjamin Döpke, Carsten Brenner, Jan C. Balzer, and Martin R. Hofmann — Ruhr-Universität Bochum, Germany

The huge progress in the field of femtosecond pulses has enabled a wide range of new applications such as two-photon microscopy or the generation of THz-radiation. State of the art sources for ultra-short pulses are solid state laser systems or fiber lasers. While solid state lasers have a complex setup and fiber lasers are limited in their wavelength, semiconductor laser systems can be miniaturized, are very cost-efficient and are variable in their wavelength by choice of material and design. However, semiconductor lasers are not commercially available sources for ultra-short pulses. The reason is that the spectral bandwidth of emitted pulses typically utilizes only a fraction of the possible gain spectrum. Because of the correlation between the spectral bandwidth and pulse duration described by the Fourier-transformation, this results in pulses much longer than the physical limits. Our approach to solve this problem is the introduction of intracavity dispersion management (IDM). This is done by using a Spatial Light Manipulator in an external cavity. We demonstrate that by introducing a combination of quadratic and cubic phase, we can produce a higher spectral bandwith and therefore shorter pulses. After external compression, we could reduce the pulse duration from 1.6 ps without IDM to 437 fs with IDM. In addition, the manipulation of the amplitude proved to further shorten the generated pulses.