Broadband diode laser

(nur in englisch verfügbar)

Light source for the coherence radar

Laser diodes with anti-reflected coating are able to emit spectrally broadened light. But the beam quality of this light is nearly like a flashlamp. Now it´s the great defiance to collect and modulate the light with different optics. So it is possible to guide this light with high efficiency trough fibers or to create a big and good collimated spot of light.

We developed two different designs. One light source is a fiber-coupled system. With a laser diode emitting at 930 nm it shines with a power of 350 mW and the spectrum has a bandwidth of more than 17 nm around a center wavelength of 930 nm. The other light source is based on a laser diode emitting at 793 nm with a bandwidth of 31 nm. Aim of this design was a good collimated light source with a homogeneous light spot. This spot should be have a diameter of 4 cm. The modified light source has now an output power of 93 mW. First measurements were accomplished on artificial dentures.

Fig. 1 Output power of broadband light sources

Fig. 2 Emission spectra

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