Continuous-wave diode-pumped Ti:Sapphire laser

Continuous-wave diode-pumped Ti:Sapphire laser

Diode-pumped CW Ti:Sapphire laser setup is based on K. Gürel et al. article [1]. 4Lasers provide all the necessary optical components according to the previously mentioned article in order to assemble the Ti:Sapphire laser. The experimental setup is presented in Fig. 1.

Figure 1. Laser setup of CW diode-pumped Ti:Sapphire laser

Two laser diodes, each delivering up to 1.5 W of output power at a wavelength of 520 nm, are used for pumping. Each pump output beam is collimated using a lens with a focal length of 4 mm and expanded along the slow axis using a pair of cylindrical lenses with focal lengths of 15 mm and 100 mm. Then the beam is focused into the gain medium with a waist radius of 24 μm x 50 μm by a spherical lens of 75 mm focal length.

As a gain medium, a 4 mm long Brewster-cut Ti:Sapphire crystal with a small-signal pump absorption of 4.1 cm−1 (± 20%) at 532 nm is recommended to be used (in this case the single-pass pump absorption at 520 nm is around 86%). The dichroic pump mirrors (R = -50 mm) have a high transmission for pump wavelengths (520 ± 20 nm) and a high reflectance for laser wavelengths. Those mirrors are placed at 15° with respect to the laser beam and 28 mm away from the beam focus in the crystal. The cavity is closed at each end with a highly reflective (HR) mirror and an output coupling (OC) mirror with a transmission of 2%, respectively. The two mirrors should be placed at a distance of 160 mm, leading to a cavity mode radius of 20 μm x 47 μm.

Note that every optical element can be customized according to the customer's request.

Expected lasing parameters

4Lasers does not take any responsibility if the achieved lasing output parameters are not as described in the [1] article. The maximum average output power of up to 650 mW at 3 W of pump power can be achieved. The optical-to-optical efficiency of 22% can be obtained. The laser output beam is characterized by the M2 factor being close to 1.0 x 1.2.

References

[1] H K. Gürel, V. J. Wittwer, M. Hoffmann, C. J. Saraceno, S. Hakobyan, B. Resan, A. Rohrbacher, K. Weingarten, S. Schilt, and T. Südmeyer «Green-diode-pumped femtosecond Ti:Sapphire laser with up to 450 mW average power,» Optics Express vol. 23, no. 23, pp. 30043–30048, 2015.