Kerstin Volz

Green semiconductor disk laser with 0.7W cw output power

We demonstrate 0.7W cw output power at 520nm from an intracavity frequency doubled optically pumped semiconductor disk laser at room temperature. High beam quality and optical conversion efficiency of 10% has been achieved.

0.7 W CW output power from a green semiconductor disk laser

We demonstrate 0.7 W cw output power at 520 nm from an intracavity frequency doubled Optically Pumped Semiconductor Disk Laser at room temperature. High beam quality and optical conversion efficiency of 10% has been achieved.

Multiwatt semiconductor disk lasers for near-infrared wavelengths

Optically-pumped semiconductor disk lasers offer high output power in combination with good beam quality. By optimizing epitaxial quality as well as thermal resistance, we have demonstrated more than 8W of continuous-wave, room-temperature emission at 1000nm. These high power-levels are tied to high optical-conversion efficiencies of more than 40%. Whereas available wavelengths for solid-state disk lasers are restricted to a set of atomic transitions, semiconductor disk lasers can be conveniently tailored to meet almost any wavelength. Building upon the high-power results at 1000nm, we have extended the emission range towards 900nm as well as 1100nm. Two prominent examples are devices realized at 920nm and 1040nm, in each case demonstrating several Watts of laser output.

0.7W Green Frequency Doubled Semiconductor Disk Laser

We demonstrate 0.7W cw output power at 520nm from an intracavity frequency doubled Optically Pumped Semiconductor Disk Laser at room temperature. High beam quality and optical conversion efficiency of 10% has been achieved.

Laser operation of the III/V compound material Ga(NAsP) grown lattice matched on (001) Si substrate

Nowadays silicon photonics gains more and more interest especially for the future architecture of Si based optoelectronic integrated circuits (OEI C). OEIC building blocks such a s modulators, detectors as well as light wave guides have been demonstrated in a down-scalable process technology. However, a commercial solution for the monolithic integration of long-term stable laser diodes has not been achieved yet, which is, however, the key device component to full y profit from silicon photonics.

Novel GaP-based dilute nitride Ga(NAsP)GaP laser material system

Realizing monolithic optoelectronic integrated circuits (OIECs) on silicon substrate would open up an exciting and completely new field of applications, i.e. optical interconnects at the chip level. In the past a lot of effort has been devoted to the growth of standard direct band gap III-V compound semiconductors on Si substrate, i.e. GaAs/Si or InP/Si. Due to the large lattice mismatch of these materials to the Si substrate large densities of threading dislocations are formed in the layers, preventing any long-term stable lasing operation of corresponding device structures. In this study the authors present a novel direct band gap material ( Ga(NAsP) ), which can be grown lattice-matched to GaP. Due to the similar lattice constant of GaP and Si, this novel material system might lead to the real monolithic integration of III/V-based optoelectronics and Si-based microelectronics in the near future

Growth of III/Vs on Silicon

The growth of III/V semiconductors on Silicon substrates has attracted great attention since quite some time as several promising device concepts rely on the defect-free integration of optically or electrically active III/V layers on Silicon substrates. The present chapter summarizes our present knowledge on III/Vs on Silicon growth with great emphasis on the defects, which can arise at the III/V-Silicon interface. We address (nearly) lattice matched growth of GaP or multinary III/Vs on Silicon as well as highly-mismatched growth of pure III-Nitrides and III-Arsenides as well as III-Antimonides on Silicon substrates. Throughout the chapter we highlight, how an understanding of growth mechanisms can lead to a minimization of defect density, making the layers suitable for device applications. Suitable characterization techniques to assess layer quality are also introduced in the text.

Modal Gain Analysis of GaNAsP Heterostructures on Silicon

We present modal gain measurements of GaNAsP multiple quantum well structures grown lattice-matched on silicon using the stripe-length method. High modal gain values of up to 80 cm-1 are observed at room temperature.

Solar Cell Characterization with High Spatial Resolution

New techniques for a solar cell characterization with high spatial resolution are introduced and evaluated both by experiments on test structures and numerical simulations. The reliability is demonstrated and technical limits are assessed.

Lasing of the III/V compound semiconductor Ga(NAsP) integrated lattice-matched to Si substrate

Ga(NAsP) multi quantum well heterostructures were grown pseudomorphically on exactly oriented (001) silicon substrates without the formation of misfit dislocations. Optical pumped lasing operation was observed at temperatures up to 125 K.