Tony Albrecht

8-W high-efficiency continuous-wave semiconductor disk laser at 1000 nm

We demonstrate more than 8-W continuous-wave output power with good beam quality (M2<1.8) from an optically pumped semiconductor disk laser. The combination of low threshold density of 470 W/cm2 and high differential efficiency of 60% results in an optical-to-optical conversion efficiency of 46% for this high output level. Good epitaxial quality and low thermal resistance allow the scaling of output power with pump spot area.

Vertical-External-Cavity Surface-Emitting Laser With Monolithically Integrated Pump Lasers

The monolithic integration of pump lasers and optically pumped vertical-external-cavity surface-emitting lasers is demonstrated. An innovative contacting scheme for the pump lasers offers high design flexibility and scalability. First devices at 1000 nm generate output powers of 2.5 W in pulsed and 0.65 W in continuous-wave operation.

High-efficiency high-power semiconductor disc laser

High efficiency, high power and excellent beam quality has been achieved in optically-pumped semiconductor disc lasers (OPS-disc laser) emitting at 1000nm. Minimizing the thermal resistance between active region and heat-sink, more than 5.5W of continuous wave (cw) output has been obtained at room-temperature. Even more remarkable, the laser characteristics corresponding to this power display differential efficiencies of better than 50% and optical conversion efficiencies of better than 40%. This combination of high power and high efficiency represents the best reported values so far. As such, a highly efficient beam converter has been realized, transforming low-brightness optical pump power into high-brightness laser emission.

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.

52.4: High Speed Green Frequency Converted Semiconductor Laser for Projection Displays

Recent progress on compact green laser for projection applications based on frequency doubled semiconductor structures will be presented. Avoiding external acousto- or electro-optical modulation for scanning laser displays, the green laser prototypes can be directly modulated in the 20–40MHz range.

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.

VCSELs for datacom applications

The use of oxide confined VCSELs in datacom applications is demonstrated. The devices exhibit low threshold currents of approximately 3 mA and low electrical series resistance of about 50 (Omega) . The emission wavelength is in the 850 nm range. Life times of the devices are several million hours under normal operating conditions. VCSEL arrays are employed in a high performance parallel optical link called PAROLITM. This optical ink provides 12 parallel channels with a total bandwidth exceeding 12 Gbit/s. The VCSELs optimized for the parallel optical link show excellent threshold current uniformity between channels of < 50 (mu) A. The array life time drops compared to a single device, but is still larger than 1 million hours.

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.

High power semiconductor disk laser with monolithically integrated pump lasers

Semiconductor disk lasers have attracted a lot of interest in the last few years due to high output power combined with good beam quality and possible wavelength engineering. One of the disadvantages is the need for external optical pumping by edge-emitting semiconductor lasers that increase packaging effort and cost. Therefore, semiconductor disk lasers with monolithically integrated pump lasers would be of high interest. We report on a novel design and experimental realization to monolithically integrate pump lasers with a semiconductor disk laser in a one-step epitaxial design. By careful design of integrated pump lasers and stacking sequence, it is possible to efficiently excite vertical emitter areas with different mesa sizes. First results are shown at 1060 nm emission wavelength with high output power out of mesa diameters of 100 μm to 400 μm. The devices can be conveniently characterized on a wafer level using dry-etched pump laser facets. In pulsed operation 1.7W out of a 100 μm diameter mesa and 2.5W out of a 200 μm diameter mesa are demonstrated. Additionally, more than 0.6W in cw operation using a 400 μm structure were achieved. In summary, an innovative approach for truly monolithic integration of a semiconductor disk laser with pump lasers has been pioneered.