Semiconductor Disk Laser (SCDL)

• Laser projection (laser TV)
• Femtosecond laser sources

980 nm to 1030 nm

The semiconductor layer structures for such devices are produced using metal-organic vapor-phase epitaxy (MOVPE). The light extraction is carried out in the growth direction (i.e. vertical to the layer structure). Due to the high excitation densities the devices are designed as bottom emitters with the substrate completely removed. The laser setup uses an external cavity. In contrast to electrically pumped surface-emitting lasers (vertical-cavity surface-emitting laser; VCSEL) the lasers are pumped optically (e.g. with edge-emitting laser diodes of a suitable wavelength).

For the generation of ultra-short pulses a saturable absorbing mirror is needed as second component. Due to the reduced thermal load this component can be fabricated as top emitter.

Semiconductor disk lasers are able to reach high output powers of several Watts with a very high beam quality. The output power scales with the size of the excited semiconductor area. The configuration of the external cavity enables applications like broad-band laser absorption spectroscopy and passive mode locking in conjunction with a SESAM (semiconductor saturable absorbing mirror) structure. By combining a SCDL and a SESAM structure it is also possible to generate laser pulses in the pico- and femtosecond region.

In cooperation with the Max-Born-Insitute for Nonlinear Optics and Short Pulse Spectroscopy a setup was developed emitting light pulses as short as 107 fs. This is the shortest reported pulse time for semiconductor lasers.